Q: Do all test blocks come with certificates of calibration?

Yes, without an exception, all of NextGen’s hardness test blocks come standard with a certificate of calibration. Soft copies can be requested for your reference.

Question 1

Is it possible to do multiple calibrations on a single NIST traceable Vickers test block?

Accepted Answer

It is possible to have a test block with multiple force calibrations. In order to calibrate a test block according to ASTM E92, 5 sets of 5 indentations are required (25 total). Therefore should you require 2 calibrations, the unit will have 50 micro indentations before being used for testing. This of course will still leave plenty of room for your other tests. The test blocks are calibrated according to ASTM E92. NextGen works in partnership with an ISO 17025 companies who certify the test blocks. Each unit comes with a certificate of calibration.

Question 2

Do you carry any hardness test bars in stock?

Accepted Answer

At all times NextGen has a certain stock of hardness test blocks readily available to meet your needs. Simply submit you quote request or contact our qualified representatives to help check the stock for you. Should we be out, our team will be happy to provide you our best lead times.

Question 3

What is the typical lead time for your NIST traceable Vickers hardness test blocks?

Accepted Answer

The typical lead time for the NIST traceable Vickers hardness test blocks is 2-4 weeks. We always try our very best to bring the lead time down as much as possible, because we understand that your needs may be urgent. Expedited options are available at an additional cost, feel free to contact us today to inquire.

Question 4

Do you ship hardness test bars internationally?

Accepted Answer

Absolute, we would be happy to assist you with international shipments. Please note that all international shipments of hardness test blocks are subject to 100% advanced payment terms for both the inventory and shipping charges. Contact us today to learn more.

Question 5

Can I expedite my order of certified test blocks?

Accepted Answer

Expedited orders for certified test blocks are an option for an extra fee. Please contact us today to learn the difference in price based on your specific test block requirements.

Question 6

Do all test blocks come with certificates of calibration?

Accepted Answer

Yes, without an exception, all of NextGen&rsquo;s hardness test blocks come standard with a certificate of calibration. Soft copies can be requested for your reference.

Question 7

Do you offer Vickers hardness test blocks for carbide value ranges of over 850HV?

Accepted Answer

Absolutely, NextGen has the full range of regular and carbide level NIST traceable hardness test block that you need. Regular Vickers test block ranges are up to 850HV and the carbide ranges are 850HV and over. Whether you need 1200HV, 1650HV or more, we have you covered. Request quote today to get the pricing for hardness test block that best meets your testing requirements. Do you offer expedited lead times for your NIST certified test blocks? Expedited lead times are always an option. The prices expedited lead time will depend on our production stage. We recommend you contact us to confirm the absolute best lead time and associated cost that we can offer. It is worth noting that our standard lead times are faster than most of our competitors on the market. If waiting is an option, we will do our very best to impress you.

Question 8

What Are the Standard Metallography Consumables Recommendations for a Polishing and Grinding Composite Materials?

Accepted Answer

Historically, there are two methods of polishing and grinding process for composite materials: Traditional Method: Grinding process &ndash; 320, 600, 800, and 1200 grits Polishing process &ndash; 6 um (polishing cloth), 3um (polishing cloth), 1um (polishing cloth) along with aluminum oxide powder or diamond suspension fluid Contemporary Method: Grinding process &ndash; 240 SIC paper Polishing process &ndash; 9um (diamond platen &ndash; Golden), 6um (polishing cloth), 1um (polishing cloth) with diamond suspension fluid Standard Engineering Recommendations: The below process offers a standard recommendation for polishing and grinding needs. This can be adjusted as needed, depending on your materials and surface finish requirements. Contact our qualified consultants to learn more. Here is a cost effective GRINDING: The most cost-effective consumables option for grinding would include a combination of our 12-inch MAGNEPAD Stainless Steel Magnetic Base Plate &ndash; Part #: SSMAG-P12 combined with the following adhesive backed grinding pads. Our recommendation based on your material and relatively smooth starting surface would be to start with: 240 Grit paper &ndash; Part #: SIC-240P12-100 600 Grit paper &ndash; Part #: SIC-600P12-100 1200 Grit paper &ndash; Part #: SIC-1200P12-100 You can always add more grinding paper grits as needed. NOTE: For optimal convenience, you would require one Steel Magnetic Base Plate per grinding paper. This combination will allow you to easily switch out your stainless steel magnetic base plates with grinding paper as needed; while benefiting from using the adhesive backed grinding paper, which is much more cost effective than magnetic grinding paper. POLISHING: After your grinding procedure, we would recommend using our 12-inch ATLANTIS Polishing Pad with Magnetic Rubber (Part #: ATL-3012-MAG) along with 1 micron DIAMAT Polycrystalline High Viscosity Diamond Abrasive (Part #: PC-1001-500). The pads can go directly onto the magnetic base plates of the main unit. They are extremely easy to switch out and have a high life-span. NOTE: Should better polishing be required, we would suggest moving into the alumina diamond suspensions. Should need additional guidance, contact us today to learn more.

Question 9

What makes an abrasive blade unique? What factors come into play when selecting a blade?

Accepted Answer

Abrasive blades are characterized by their abrasive type, bond type and hardness. The main factor when deciding which blade is right for you will be heavily dependant on your material hardness and whether it is a ferrous or a non ferrous metal.

Question 10

What are the two main types of abrasive sectioning blades?

Accepted Answer

Resin bonded blades and Resin-rubber bonded blades. Resin bonded have less smell, quicker wear, less sample burning and more versatile. Resin-rubber bonded blades certainly have a longer lifespan but will have a burnt rubber smell during the cutting process. They often burn a sample and are usually much more difficult in finding the best blade for the application.

Question 11

What blades can I use for my precision cutter?

Accepted Answer

Diamond wafering blades are the most common for precision sectioning, however, cubic boron nitride CBN blades are sometimes more efficient. Wafer cutting is often used for sectioning delicate samples or within a precise location.

Question 12

What are the main types of hot compression mounting resins? What colours are available and what are their uses?

Accepted Answer

Phenolic Resins (standard colors are black, red and green) &ndash; low cost and a variety of colours Acrylic Resins (clear) &ndash; excellent clarity Diallyl Phthalate Resins (blue and black) &ndash; provides a harder mounting support edge next to the specimen often used for coatings or heat treating sample analysis Epoxy Resins (glass-filled) &ndash; provides a harder mounting support edge next to the specimen often used for coatings or heat treating sample analysis Conductive Resins (phenolics with copper or graphite filler) &ndash; special resins can be made conductive for scanning electron microscopes SEM to prevent the specimen from building up a charge

Question 13

How do I determine which grits of metallographic abrasives and polishing pads/consumables to achieve the best finish for my specimen analysis?

Accepted Answer

The best way is to send NextGen your samples and have our metallographic experts work with your samples to working out the best consumables to achieve your desired finish. Contact a sales representative today to have your samples evaluated!

Question 14

What are the standard dimensions of your Rockwell Hardness Test Blocks?

Accepted Answer

The standard dimensions of the Rockwell C hardness test blocks are as follows: Square Rockwell Hardness Test Blocks Width: 50.90mm (~2&Prime;) Depth: 50.90mm (~2&Prime;) Thickness: 6.85mm (~0.25&Prime;) Request quote to get your consumables price catalogue.

Question 15

What are the standard dimensions of your Brinell Hardness Test Blocks?

Accepted Answer

The standard dimensions of the Brinell hardness test blocks are as follows: Square Brinell Hardness Test Blocks Length: 152.40mm (6&Prime;) Depth: 50.90mm (~2&Prime;) Thickness: 6.85mm (~0.25&Prime;) Request quote to get your consumables price catalogue.

Question 16

The etchants indicate an expiry date of roughly 3 months. What happens if these consumables are use past the expiry date?

Accepted Answer

After the 3 months expiry date, the etchants may still produce the expected results, with no apparent effect on quality. This is especially true if the etchants are stored in a cool, dark and dry environment. The issue is that not all of them will last longer than 3 months. Some of them will degrade to the point of being unusable around 90 days or so. Because of this, all etchants have a 3-month shelf life. Occasionally we advise customers to continue using their etchant until they no longer get the results they need. In other cases where safety is tightly regulated, they may not have this option. Learn more by contacting our Quality Consultants today.

Question 17

What is Diamond grinding paper and when is it used?

Accepted Answer

At 8000 HV, mohs 10, diamond is acknowledged as the hardest material around. Its structure is of cubic crystal. It is available either as an artificial or natural product. While diamond is perfect for coarse grinding, its cost renders it an ineffective grinding material for everything except hard ceramics. For metallographic purposes, specifically as a rough polishing abrasive, polycrystalline diamond is ideal.

Question 18

What is Zirconia grinding paper and when is it used?

Accepted Answer

Zirconium silicate or Zircon is a not-so-commonly used coarse grinding abrasive. Because of its extreme toughness, it lasts longer. But, it isn&rsquo;t, in general, as hard or sharp as the more popular abrasives. It thus needs a higher pressure to be effective. Usually, the 120 or 60 grit sizes are considered the most useful for metallographic grinding applications with Zircon. The particle size for metallographic abrasives is classified typically by their grit size or the average particle size measured in microns. Grit size refers to the particle size if sized or classified with mesh screens. Grit size, in general, represents the number of wire mesh or wires per given area. Larger grit numbers thus represent more or smaller mesh screen openings, and mean smaller particle sizes. For instance, a 120 grit particle is around 105 microns in size, while a 1200 grit particle is 2.5 microns in size. The variance between the P-grading system used in Europe and the more prevalent CAMI or ANSI standard is mainly due to the European number being based on how many openings there are if the wire mesh width is not considered in the calculation. For larger particles, therefore, Europe&rsquo;s P-grading is about the same as the CAMI or ANSI number. For example, 120 grit is equivalent to P120 grit. For finer particles, on the other hand, you will see a much bigger value such as P4000 grit compared to 12000 grit.

Question 19

What are the primary types of polishing pads?

Accepted Answer

CERMESH Metal Mesh Cloth &ndash; The wire mesh material is coarse as well as intermediate lapping/polishing. The wire&rsquo;s texture allows the abrasive be semi-fixed. It therefore offers the edge of minimizing damage while increasing stock removal. POLYPAD Polishing Pad &ndash; The synthetic polyester polishing pad works similar to a nylon pad, except that the Polypad is a lot more durable. It is ideal for use in intermediate polishing tasks. TEXPAN Polishing Pad &ndash; The pad is the most frequently used cloth for intermediate polishing jobs. The polishing pad is non-woven. CHEM 2 Polishing Pad (Black) &ndash; The porometric polymer pad has the same consistency of a rubber type of pad. The CHEM 2 Black pad possesses a low nap, but acts as a polishing pad for intermediate applications. Its performance is somewhere between that of a low nap pad and a high nap pad. DACRON II Polishing Cloth &ndash; The low nap type of polishing pad is primarily used for polishing with a 1 &ndash; 15 micron diamond abrasive. It is the most frequently used intermediate polishing pad for metals in Europe. It has a high nap that allows the pad to provide a very gentle and soft polishing action. GOLDPAD Polishing Pad &ndash; A low-napped pad for intermediate polishing applications, it is mainly used with a 1 &ndash; 9 micron diamond. ATLANTIS Polishing Pad &ndash; A low napped woven pad for final applications, it has a foam backing that allows for better matting to the sample. It is a superior polishing pad used with 1 &ndash; 6 micron diamonds. NYPAD Polishing Pad &ndash; The low napped polishing pad made from silk is ideal for intermediate polishing applications. It is used mainly with diamond intermediate abrasives. MICROPAD Polishing Cloth &ndash; The most prevalent high nap pad used for final polishing of most polymers and metals, the nap offers a very gentle and soft polishing action. TRICOTE Polishing Pad &ndash; The tight high napped pad is ideal for final polishing of most metal materials. It is equipped with a tighter nap compared to the MICROPAD Polishing Pad. MOLTEC 2 Polishing Pad &ndash; The wool polishing cloth is ideal for final polishing use, and comes with an extremely high nap. It is typically used for the final polishing of metals where edge retention is not a big factor. NAPPAD Polishing Pad &ndash; Another high napped variety for final polishing, the pad is mostly used form most polymers and metals. Compared to the MICROPAD, the NAPPAD has a higher nap that provides an extremely gentle polishing action. It is quite useful for polishing softer materials like aluminum, copper, and austentite steels. FELTPAD Polishing Pad &ndash; The thick felt pad is mainly used for the final polishing of glass and other area parts with large surfaces.

Question 20

What are the benefits of metallographic polycrystalline diamond polisher use in the polishing cycle?

Accepted Answer

Very uniform surface finish High cutting rates More uniform distribution of particle size The self-sharpening abrasives offer high removal rates Tougher/harder particles Blocky shape Hexagonal microcrystallites that are similarly hard in any direction Very rough surface because of more cutting points A surface area 300 times more than monocrystalline diamonds Absence of abrasion-resistant directionality as the abrasion is independent of the orientation of the particle

Question 21

What is the ideal use for polycrystalline diamonds in the polishing cycle?

Accepted Answer

Polycrystalline diamond is most efficient when used for the initial application of several diamond beads/extenders for pad wetting. Notice that the pad saturation is not necessary. Neither is it recommended. Additional dispensing is typically dripped on the surface at 1 to 2 drops per 10 to 15 seconds, depending on the speed of polishing and the sample?s surface area. For the preparation of mineral and ceramic specimens, the recommendation is the alternate dispensing of diamond and colloidal silica (or SIAMAT colloidal silica). This results to a chemo-mechanical polishing (or CMP) action that considerably improves removal rates, lowers subsurface damage, and makes the surface finish better. The technique is ideal for use with 6 micron diamonds and other smaller polycrystalline diamonds. For best results for the application, it is recommended to clean the samples and the cloth during the cycle?s final 15 seconds. Allow running water to flow on the surface of the polishing pad.

Question 22

What is the ideal application of Monocrystalline Diamonds in the polishing cycle?

Accepted Answer

The best use of monocrystalline diamond is during the initial application of several diamond beads/extenders for the initial pad wetting. Notice that the pad saturation is neither recommended nor necessary. Additional dispensing is typically dripped on the surface at 1 to 2 drops for every 10 to 15 seconds, depending on the sample?s surface area and polishing speed. For ceramic and mineral specimen preparation, it is best that colloidal silica and diamond be dispensed alternately. This results to a chemo-mechanical polishing action that considerably improves removal rates, lessens subsurface damage, and enhances surface finish. The technique is ideal for use with 6 micron diamonds and other smaller polycrystalline diamonds. For best results for the application, it is recommended to clean the samples and the cloth during the cycle?s final 15 seconds. Allow running water to flow on the surface of the polishing pad.

Question 23

What are the common abrasive sectioning blade types?

Accepted Answer

Resin bonded blades &ndash; more versatile, higher wear, less sample burning, and less smell Resin-rubber bonded blades &ndash; tends to burn the sample, burnt rubber smell, longer life, and harder to find the appropriate blade

Question 24

When should you use abrasive blades?

Accepted Answer

The selection of the right abrasive blade to use depends on the cut-off machine&rsquo;s design, and to a large degree, the preference of the user. In general, abrasive blades are characterized by the type of abrasive, hardness, and bond type. Determining the right blade depends on the material or hardness of the metal, and whether the metal is ferrous or non-ferrous. In common practice, it usually comes down to blade life and odor. Resin/rubber blades tend to smell more since the rubber will slightly burn during the cutting process. But, this type of blade wears more slowly, and thus lasts longer. Resin blades, on the other hand, don&rsquo;t produce the smell of burnt rubber and are more versatile. However, the break down more easily. Resin blades likewise offer a slightly better cut. This is because the abrasive is continuously renewed, producing a cleaner cut in the process. It is also worth noting that the traditional, old-fashioned technology used to produce abrasive blades resulted to highly specialized resin/rubber blades. Thus, finding the right resin/rubber hardness, blade thickness, and abrasive size that matches the properties of the sample as well as the cutting machine parameters required lots of experimentation and testing. In the past, the resin/rubber blade was more common in the US. However, with the improvement of resins in recent years, the trend has seen a gradual shift towards resin bonded types of abrasives. In contrast, resin bonded blades have been more popular in the Asian and European markets for many years now.

Question 25

What&rsquo;s precision cutting, and when is it used?

Accepted Answer

Precision wafer cut is most often applied with a diamond wafering blade. For some materials, however, cubic boron nitride (or CBN) is the more appropriate and efficient watering blade to use. Optimal wafer cutting is also done by optimizing the abrasive size and concentration, and choosing the most suitable cutting load and speed. Precision wafer cutting is applied to section extremely delicate samples and to section samples to a quite precise location. Typically, precision wafering saws are equipped with micrometers to accurately align and position the samples. They also have variable cutting land loading speed control. The typical precision wafering saw ranges in speed from 50 to 1500 rpm or 300 to 3000 rpm. Faster saws are needed to section extremely hard materials like treated steals, minerals, and ceramics.

Question 26

When is wafering sectioning used in lieu of an abrasive sectioning blade?

Accepted Answer

A diamond wafering blade is often used for sectioning delicate materials that require a precise cut. When sectioning with a wafering blade, it is important to consider the load, speed, and diamond size and concentration. The applied load and cutting speed are functions of the material to be cut. Commonly, diamond wafering is performed at a speed of anywhere between 50 and 5000 rpm with varying loads from 10 to 1000 grams. In general, a harder specimen is cut at a higher speed and load (for instance, minerals and ceramics) as well as more brittle samples are cut at lower speeds and loads (such as electronic silicon substrates). A number of factors must be considered when choosing the right watering blade, including the diamond concentration (high and low), diamond size (medium or fine), diamond bond (metal plate), blade thickness, and diameter. Diamond concentration is crucial since it affects the applied load directly during cutting. For instance, brittle materials like ceramics need a higher effective load to section, unlike ductile materials like metals that need more cutting points. Thus, low concentration blades are better when sectioning hard brittle materials like ceramics. On the other hand, high concentration blades are preferred for ductile materials that contain a large portion of plastic or metal. The diamond bonding material likewise considerably affects the cutting performance of the blade. A metal plated wafering blade requires periodic dressing to keep it in top performance. Contrary to what many people think, the cutting performance doesn&rsquo;t diminish when the diamond is taken out of the blade. The metal bond, in reality, mainly smears over the diamond, and blinds the diamond abrasive. The smeared material is taken away and the cutting rate is restored with periodic dressing.

Question 27

What are the main categories of compression mounting compounds?

Accepted Answer

The different types of compression mounting resins include: Acrylic Resins (clear) Phenolic Resins (available in standard colors of red, green, and black) Epoxy Resins (glass-filled) Diallyl Phthalate Resins (black and blue) Conductive Resins (phenolics w/ graphite or copper filler)

Question 28

Explain the main differences among different types of compression mounting compounds.

Accepted Answer

Phenolics &ndash; Generally, phenolics are utilized because of their comparatively low cost. Phenolics are likewise available in various colors. Acrylics &ndash; The primary use of compression mounting acrylics is due to its excellent clarity. It is particularly important in locating specific features in the specimen mount. Epoxies/Diallyl Phthalates &ndash; Glass-filled epoxy and diallyl phthalate are types of compression mounting resins utilized for providing a tougher mounting support edge around the specimen. The resins are typically used as support for the coatings&rsquo; edges, heat treated samples, as well as other specimens that require better flatness. There&rsquo;s no apparent gap between the mounting material and the specimen. The glass-filled epoxies offer excellent support to the edge of the specimen even in extremely hard samples. Specialized Compression Mounting Resins &ndash; The addition of fillers like copper or graphite enables the compression mounting compounds to be more conductive. A conductive mount is used for scanning electron microscopes (SEM) to keep the specimen from accumulating a charge. A conductive mount is also used for samples that require electrolytic etching or polishing.

Question 29

What is a Silicone Carbide Grinding paper and when is it used?

Accepted Answer

SIC abrasive is manufactured using the high temperature produced in the reaction between carbon and silica. Its structure has a hexagonal-rhombohedral crystal shape. Its hardness is around 2500 HV. The abrasive is ideal for grinding and cutting because of its sharp edges and hardness. It likewise has enough brittleness. It easily cleaves to create new sharp edges (self-sharpens). SIC is superior in maximizing the cutting rates, while helping minimize subsurface and surface damage. In metallographic applications, it is used in abrasive blades as well as for coated abrasive grinding paper that range from the extremely coarse 60 grit to the extremely fine 1200 grit size. Coated or bonded SIC abrasive papers are specifically designed to give the abrasive a big number of cutting points. This is possible by proper alignment of the abrasive particles that are about normal to the backing. It must be noted that coated abrasives aren?t quite coplanar. SIC papers thus produce maximum efficiency (stock removal, cut rate, and minimal damage) since new abrasive gets exposed and the old abrasive is broken down.

Question 30

What is Alumina grinding paper and when is it used?

Accepted Answer

A naturally occurring material, Alumina comes in either the alpha (hard at 2000 HV, mohs 9) or the gamma (soft at mohs 9) phase. The Alumna abrasive is mainly used for final polishing due to its durability and hardness. Unlike SIC abrasive, alumna is easier to break down into colloidal or submicron particles. It is worth noting that bigger coated or bonded grit alumina sizes are available commercially. But, they are not recommended for metallurgic uses because they turn dull. This results to a lower cut rate and a higher subsurface and surface damage.

Question 31

What is the expected useful life of hardness blocks?

Accepted Answer

While some blocks sometimes self-destruct within a short period due to heavy use, some can last for several years. In general, high force testing can destroy soft blocks in about a month, particularly when it requires daily verification. Changes in ISO and ASTM requirements can render a block useless. This is what happened to pre-NIST traceable HRC back in 2000, as well as blocks calibrated in the absence of verified indenters pre-E180-07.

Question 32

I ordered a 300 HV 0.5 microindentation test block, but got a 370 HV 0.5 instead. I intend to use it for checking a special part I&rsquo;m fabricating. Wouldn&rsquo;t it be possible for me to get exactly the value I need?

Accepted Answer

You use test blocks to verify the calibration of the tester, and not your part. Although it is ideal to use a block that&rsquo;s as close as possible to your part&rsquo;s hardness, it isn&rsquo;t that critical. That being said, blocks are selected from different heat treat lots to get the best possible match. Different indenter and force combinations can likewise affect the result of your received block value. It is recommended that you consider the suggested hardness levels listed in ISO and ASTM documents.

Question 33

How can if determine the proper hardness scale to use?

Accepted Answer

You can start with the part specifications with your customer or within your organization. Part specifications are sometimes listed with common scales like HRC, although you can&rsquo;t do the scale on your part &ndash; the reason being the part may be too thin or possesses a case hardness. ISO and ASTM charts provide guidance on the minimum thickness. Take care when using testers by conversion or those that convert hardness scales electronically. Conversions cannot be accredited.

Question 34

What does a master calibration kit include?

Accepted Answer

The Master Calibration Kits we produce give customers the ultimate Quality Control tool. Every kit contains test blocks or a single block, as well as the penetrator unit used for calibrating them. Matching the blocks to a particular penetrator establishes a set relationships, which can then be disregarded as probable variables in hardness test systems. If a problem crops up, an available master kit lets you accurately and promptly determine if the source is your hardness tester. All the blocks that come with our kits have been calibrated using a tester, the accuracy of which has been verified with NIST traceable depth and load measuring devices. The kits come with a polished wood case, as well as certificates that cover all applicable standards.

Question 35

Do Brinell test blocks have circles and grids?

Accepted Answer

Circle and gridded blocks are sold separately. The most common block dimensions are 6 x 2 x &frac34;&rdquo;. Other available dimensions 2 x 2&Prime; and 6 x 4 1/2 x &frac34;&rdquo;, depending on ASTM E10-17 dimension rules. Call to check for availability and prices. Materials used are brass, aluminum, or steel, depending on the hardness required.

Question 36

WHAT ARE THE STANDARD DIMENSIONS OF YOUR VICKERS HARDNESS TEST BLOCKS?

Accepted Answer

Vickers Hardness Test is a flexible hardness test technique that is used to measure both macro and microhardness. It is appropriate for a variety of applications and materials and has a wide load range. A lot of people believe that the Vickers hardness test is simpler to use than other hardness tests for the following reasons: The procedure can be carried out using a universal or micro hardness tester; The calculations necessary are independent of the indenter size; The same indenter (a pyramidal diamond) can be used for all materials, regardless of hardness. Your indentation will deform the surrounding material and change its properties when you do a Vickers hardness test, regardless of the microhardness tester you employ. The Vickers hardness testing standards specify a specific distance between multiple indentations in order to prevent errors in interpreting perceived hardness. These are the standard dimensions of NextGen&rsquo;s Vickers Hardness Test Blocks: Micro Vickers &ndash; 1kg. or under Range: from 80 UVN &ndash; 2200 UHN Diameter: 1.25&Prime; Heavy Load Vickers &ndash; from 1kg. &ndash; 50kg. 2.0&Prime; Square &ndash; 50 x 50mm 1/4&rdquo; Thickness &ndash; 6.35 mm Range: 80 UHN &ndash; 800 For 800 & up 1.25&Prime; diameter (32mm) Looking for a quote? Click here to obtain a personalized quote!

Question 37

WHAT ARE THE STANDARD DIMENSIONS OF YOUR KNOOP HARDNESS TEST BLOCKS?

Accepted Answer

The Knoop hardness test is used for microhardness testing (loads less than or equal to 1 kgf). Hence before putting the sample material into the microhardness tester, its surface should be highly polished or electropolished. In the microhardness testing range, the Knoop hardness test is an alternative to the Vickers hardness test and can be carried out on the same universal or micro hardness testing apparatus. It is primarily employed to prevent breaking in brittle materials and to make it easier to measure the hardness of thin layers. The indenter used in the Knoop hardness test is a pyramidal diamond, just like in the Vickers hardness test. However, the pyramid is extended rather than symmetrical. The length diagonal of the indent is measured optically to determine the Knoop Hardness (HK). These are the standard dimensions of NextGen&rsquo;s Knoop Hardness Test Blocks: Micro Knoop &ndash; 1kg. or under Range: from 80 KHN 700 Diameter: 1.25&Prime; Heavy Load Knoop &ndash; from 1kg. &ndash; 50kg. Range: from 80 KHN &ndash; 700 1.25&Prime; Square Looking for a quote? Click here to obtain a personalized quote!

Question 38

What&rsquo;s the benefit of the grid over circle spacing for Rockwell test block testing?

Accepted Answer

Square Pattern &ndash; The entire block is grid patterned. The problem with this design is that soft blocks create bigger indents, and don&rsquo;t always satisfy ASTM E18-17e1 for the distance between the edge and another indent. You can use any other square to solve the issue. Circle Pattern &ndash; The design solves the distance problem between indents, thereby meeting the standard. There are complaints of excessive space wastage. This, however, is the ASTM E18-17e1 rule.

Question 39

When fabricating test blocks, how do you guarantee compliance with set industry standards?

Accepted Answer

We directly work with brass and steel mills for the specific chemical composition. We perform all machining processes in-house, at the calibration site. These include grinding, lapping, and polishing. We perform 100% inspections to make sure each single test block meets ASTM physical requirements in terms of flatness, thickness, parallelism, and surface roughness. Each Rockwell test block supports compliance to NADCAP.

Question 40

Which certifications are your test blocks compliant with?

Accepted Answer

The test blocks are manufactured in an ISO/IEC 17025 accredited lab by the American Assoc. for Lab. Accreditation (A2LA).

Question 41

At what scales do you produce test blocks?

Accepted Answer

Rockwell Regular & Superficial scales Vickers Micro-indentation &ndash; for loads starting from 10gf up to 1kgf Vickers Micro-indentation &ndash; for loads starting from 1kgf up to 120kgf Knoop Micro-indentation &ndash; for loads from 10gf up to 1kgf Brinell: HBW5/250, HBW10/1000, HBW5/750, HBW2.5/62.5, HBW2.5/187.5, and HGW10/3000.

Question 42

What do you recommend for verification testing in-house?

Accepted Answer

Ensuring compliance to ISO, ASTM, and JIS standards is crucial in user-performed hardness testing. The standard under which the lab operates determines the frequency. Common reasons for performing verification tests include: Start of production for the day Changing test force Changing indenters

Question 43

What&rsquo;s the proper indentation spacing on Rockwell and Brinell test blocks?

Accepted Answer

Based on JIS, ASTM, and ISO standards, the proper distance between 2 adjacent indentations&rsquo; centers is a minimum of 3 times the indentation&rsquo;s diameter. The distance any indentation&rsquo;s center to a test piece edge must be a minimum of 2 &frac12; times the indentation&rsquo;s diameter.

Question 44

What&rsquo;s the proper spacing for Vickers test block indentations?

Accepted Answer

Based on ASTM Standards, measuring the distance between 2 indents or the edge of a test piece and an indent involves at least 2 &frac12; times the indentation&rsquo;s diagonal (dV). Based on JIS and ISO standards, the distance between 2 indent centers is a minimum of 3x the indent&rsquo;s diagonal for copper, copper alloys, and steel, and a minimum of 6 times for lighter metals, tin, lead, as well as their alloys. The distance from an indent&rsquo;s center and the test piece edge must be a minimum of 2 &frac12; times the dV for copper, steel, and copper allows, and a minimum of 3x for light metals, tin, lead, as well as their alloys.

Question 45

What&rsquo;s the proper spacing for Knoop test block indentations?

Accepted Answer

Based on ASTM Standards, distance between 2 indents is a minimum of 2 times the indentation&rsquo;s diagonal (dK), and 2 &frac12; times the indentation&rsquo;s width (dW). The distance between an indentation&rsquo;s center and a test piece edge is at least 1 dK or 2 &frac12; times the indentation&rsquo;s dW. Based on ISO Standards, distance between 2 indents is at least 2 times the indentation&rsquo;s dK, and 3 &frac12; times the indentation&rsquo;s dW. The distance between an indentation&rsquo;s center and a test piece edge is at least 1 dK or 3 &frac12; the indentation&rsquo;s dW. Based on JIS Standards, the distance between an indentation and a test piece edge is a minimum of 3 times the short dW. The distance from one indentation to an adjacent indentation is at least 2 &frac12; times the short dW, or a minimum of the long dK. If 2 indentations have different sizes, the spacing minimum is based on the short dW of the bigger indentation.

Question 46

Is there a detrimental affect to polishing on the vibromet in the colloidal silica for extended amounts of time?

Accepted Answer

It is common to polish for extended periods of time (hours) on the vibratory polisher. This is most common for very hard materials like engineered ceramics. The effect of over polishing on metals it that you can begin to introduce relief or edge rounding where the specimen meets the mounting compound. This can also happen if the specimen is comprised of various phases/materials of varying hardness. A good example is a PCB where you might have soft materials like tin or copper alongside harder materials like ceramic. The best practice is to play with times relative to your specimen and analysis. Checking the specimen on an optical microscope every 30 minutes is helpful when developing procedures for vibratory polishing. Also, keep in mind the colloidal silica will crystalize if allowed to dry out or dehydrate. I hope this is helpful.

Question 47

How many indentations can you make on a gridded Rockwell test block?

Accepted Answer

The gridded Rockwell test blocks has 182 distinct squares perfectly spaced out according to the ASTM E18 standard. Therefore you can make 182 indentations per block.

Question 48

When do I need to use a gridded Rockwell test block?

Accepted Answer

When testing on lower Rockell hardness range test blocks, the indentations are larger, therefore gridded blocks can serve an optimal solution for help space the indentations out to be in tune with the ASTM E18 standard. Testing with higher hardness range test blocks results in smaller indentations, therefore the operator may be comfortable using the standard test blocks.

Question 49

What is the error tolerance for the HRB Test Blocks according to the ASTM E18 standard?

Accepted Answer

According according to the latest ASTM E18 (v. 2022) specifications. The tolerance on the HRB test blocks are as follows: If HRB is less than 88 the acceptable tolerance is +/- 2.5. If HRB is greater than 88 the tolerance is +/-1.0. Learn more by contact our qualified consultants today.

Question 50

What are the international standards for Hardness Test Blocks, Indenters and Hardness Testing Accessories?

Accepted Answer

ASTM E18 is the industry standard for Rockwell hardness testing of metallic materials. This specification includes both theory and standard practice statements. For those companies Nadcap accredited in heat treat where the AC7102/5 for hardness and conductivity testing is included, an additional layer of requirements comes into play. ASTM E18 lists three types of verification testing: direct verification, indirect verification, and daily verification. ISO 6508 specifies the method for Rockwell regular and Rockwell superficial hardness tests for metallic materials and is applicable to stationary and portable hardness testing machines. For specific materials or products, other specific International Standards apply (for instance, ISO 3738&#8209;1 and ISO 4498). Standard Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 Brinell Hardness Test Blocks &mdash; ASTM E-10 and ISO 6506 Vickers and Knoop Hardness Test Blocks &ndash; ASTM E-384 and ISO 6507 If you have any other questions or would like to obtain a personal quote, please click here.

Question 51

What is the Major Load for Standard & Superficial Rockwell Hardness Test Blocks?

Accepted Answer

The determination of the Rockwell hardness of a material involves the application of a minor load followed by a major load. The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The depth of penetration from the zero datum is measured from a dial, on which a harder material gives a lower measure. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly, thus obviating tedious calculations involved in other hardness measurement techniques. For Standard Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 Major Load varies all the way from 60KG for HRA, HRF, HRH, HRL, & HRR scales to 150KG for HRC, HRG, HRK, & HRP scales. For Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 Major Load varies from 15KG at Hardness Scale HR15N to 45KG at Hardness Scale HR45Y. Click here if you are looking to obtain a personal quote!

Question 52

What penetrators Standard & Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 use?

Accepted Answer

A penetrator is used to measure the hardness of a material. The Rockwell test system is based on the idea that the depth of penetration decreases as the hardness of the object being tested increases. The minor load is applied to the surface in order to condition it. The major load is applied and then released gradually. The minor load remains, but the difference between the depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. The specified penetrator was installed into the indenter fixture. A flat anvil or V-shaped anvil is installed to support the specimen. The following penetrators are used in Standard Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508: C Diamond, A Diamond (Carbide), 1/16&Prime; Ball, 1/8&Prime; Ball, 1/4&Prime; Ball and 1/2&Prime; Ball. Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 use, on the other hand, such kinds of penetrators: N Diamond, 1/16&Prime; Ball, 1/8&Prime; Ball, 1/4&Prime; Ball, 1/2&Prime; Ball. If you have any other questions or want to obtain a quote, click here.

Question 53

What are the ASTM and ISO standards for Brinell Hardness Test Blocks and Vickers and Knoop Hardness Test Blocks?

Accepted Answer

ASTM E-10 and ISO 6506 standards are used in Brinell Hardness Test Blocks. ASTM E-384 and ISO 6507 standards are used in Vickers and Knoop Hardness Test Blocks. The standard test method for Knoop and Vickers Hardness Testing of Materials is ASTM E384. Test loads are are typically in the range of 100 to 500 gram, however can be as low as 1 gram and as high as 1,000 grams. A geometrically similar indentation at all test forces is usually produced by the Vickers indenter. ISO 6507 specifies the Vickers hardness test method for the three different ranges of test force for metallic materials, including hard metals and other cemented carbides. Using ASTM E10 Brinell testing is a method of hardness testing using a tungsten carbide ball as the indenter. The indenter is brought into contact with the planar surface of a test specimen and held with a test force for a specified dwell time. The magnitude of the force and the diameter of the ball can vary depending on the material being tested. Methods of direct and indirect verification of testing machines used for determining Brinell hardness in accordance with ISO 6506&#8209;1 and when these two types of verification have to be performed are specified by ISO 6506. You can click here to request a personalized quote.

Question 54

What material is being used in Standard and Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508?

Accepted Answer

Standard Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 use the following materials: Steel Brass Carbide Superficial Rockwell Hardness Test Blocks &ndash; ASTM E-18 and ISO 6508 use such materials: Steel Brass In tungsten carbide hardness testing Rockwell hardness of HRA is often used. HRA, named Rockwell Hardness A scale, which as the initial pressure uses 98.07N (equal to 10kgf), use a diamond pressure head with 120&deg;cone apex angle or steel ball with 1.59, 3.18mm in diameter and then pressurized to 588.4N (equal to 60kgf). These brass alloys are single-phase alloy, which metallurgically we call &ldquo;Alpha&rdquo; phase, which has a face-centred cubic structure. The solubility of zinc in copper is 32.5% at the solidus temperature of 900&#730;C and 30% at room temperature. The brasses used in cartridge cases are entirely alpha phase and are ideally suited to cold working having superior ductility to the copper-zinc alloys. Looking for a quote? Click here to obtain a personalized quote!

Question 55

What is electrochemical etching in Metallography Etching and Cleaning?

Accepted Answer

Electroetching is a metal etching process that uses a solution of an electrolyte, an anode, and a cathode. The metal piece you want to etch is connected to the positive terminal of a source of direct electric current. To reduce unwanted electrochemical reactions, the anode and cathode should be of the same metal. The cation in the electrolyte should also be of the same metal as the metal in the battery. When the current source is turned on, the anode metal dissolves and turns into the same cation as in the electrolyte, and at the same time, an equal amount of the cation in the solution turns into metal and is deposited on the cathode. Depending on the voltage used and the electrolyte concentration at the anode and cathode, other, more complex electrochemical effects may occur, but the main ones are dissolution at the anode and deposition at the cathode where. To get a personal quote on Metallography Consumables, you can click here.

Question 56

What is chemical etching in Metallography Etching and Cleaning?

Accepted Answer

Chemical etching is a technique used to remove the material with a high-pressure, high-temperature chemical spray, creating a permanently etched image in metal. A resist is applied to the material&rsquo;s surface and is selectively removed, revealing the underlying metal. This process is then repeated to create the desired image. An etching machine uses a corrosive reaction between a chemical and a material to create an image. The machine is then heated and sprayed at high pressure to amplify the effect. The chemical spray dissolves the unprotected metal areas, etching the material atom by atom for a smooth, burr-free finish. Almost any metal and metal alloy can be chemically etched. This includes steel and stainless steel, nickel, copper and aluminum. Most metals are etched using a ferric chloride etchant which is safe to use and can be recycled. Ferric chloride can be recycled and reused. Other types of proprietary etchants, such as nitric acid, are used for specific types of metals and alloys. Click here to obtain a personal quote on Metallography Consumables or if you have any other questions.

Question 57

Do Diamond Cutting Blades Wear out?

Accepted Answer

Unfortunately, not all Diamond Blades last forever. If you know when your Diamond Blade is starting to wear down, it will slowly start to lose its effectiveness. The results of using a worn diamond blade are hard to see, but if you compare a brand new blade to a week-old blade that has been used, you will definitely notice the difference. If you learn to notice when it wears out, then you will save time, and your work will become more efficient. Nevertheless, a diamond blade is not blunt or have dull edges like a Jigsaw Blade or Sabre saw blade. This means you can&rsquo;t just replace it when you notice it&rsquo;s dull. You have to pay attention to the type of blade cut and if it is different from the first time you use it. Your diamond blade will likely need to be replaced even if it still cuts. A fast, clean cut is always better than a slow, dull one. Click here to obtain a quote or if you have any more questions.

Question 58

Why is the grinding and polishing step necessary in metallographic preparation?

Accepted Answer

Preparation of material for microscopic examination is the most common method used for mechanical specimens. The surface preparation necessary for a specific analysis or examination is determined by the type of analysis or examination being performed. The process of preparing mechanical specimens involves removing the material on their surface until the desired result is achieved. This can be done with progressively finer particles until the desired surface finish is reached. Proper grinding removes damaged or deformed surface material while limiting additional surface deformation. The goal is to produce a polished surface with minimal damage that can be easily removed during polishing. Grinding removes material using a fixed abrasive particle that produces small chips of the specimen material. The process of making small chips with a sharp abrasive grain produces the lowest amount of deformation in the specimen while providing the highest removal rate. Click here to obtain a personal quote on Metallography Consumables from NextGen.

Question 59

What is Diamond Suspension, and what is it used for?

Accepted Answer

Diamond suspensions are used in the sample preparation stage to quickly remove raw materials and produce perfectly polished surfaces for analysis. The type of diamond suspension to use depends on the material being polished and the desired surface finish. Monocrystalline diamond suspensions are generally good performers, but in some cases, Polycrystalline diamond suspensions will be required. Polycrystalline diamond is particularly effective at removing stock and polish from hard or sintered materials. Glycol Based Suspensions: A water-soluble and environmentally friendly diamond suspension mixed with glycol lubricant. Ideal for manual application or automatic &ndash;drip&rdquo; dispensing systems. Colour-coded for easy identification of micron size. Water Based Suspensions: Water soluble and environmentally friendly, this 99% water-based formula is recommended for manual application or automatic &ndash;&rdquo;spray&rdquo;/&rdquo;drip&rdquo; dispensing systems, where the lubricant is also applied. DiaLube Diamond Suspensions: Water soluble and environmentally friendly diamond suspension pre-mixed with a propylene glycol-based polishing lubricant. Excellent for quick application of both abrasive and lubricant without the need for precise dripping ratios. Alcohol-Based Slurries: An alcohol-based slurry made with 100% polycrystalline diamond, recommended for water-sensitive materials such as zinc, magnesium, and steel with non-metallic inclusions. Use with alcohol-based lubricants only. Recommended for manual application or automatic &ndash;spray&rdquo;/&ndash;drip&rdquo; dispensing systems, where the lubricant is also applied. If you would like to obtain a personal quote on Diamond Abrasive Suspension and other Metallography Consumables, please click here.

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Consumables – Hardness Testing, Metallography, Tensile and More…

Metal Testing Equipment

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Products

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Hardness Test Blocks, Indenters and Hardness Testing Accessories

Metallography Consumables