TestStar Series Grips and Fixtures for Hydraulic UTMs

The series covers tension, compression and three-point bending with thirteen grips and fixtures, from a 100 N side-action grip for spandex wire to a 300 kN (67,443 lbf) wedge grip for flat and round specimens of metal and composite.

The grips are grouped by how they hold the specimen. Three snubbing grips wrap filament, thread or steel wire around a drum, two side-action grips clamp textile and spandex wire from the side, and three wedge grips rated 30, 100 and 300 kN hold by wedge action.

Three compression fixtures run from 500 N for non-metallic materials up to 100 kN, and two bending fixtures take flat and round metallic specimens at 10 kN and 100 kN.

The series supports testing to ASTM D638, ISO 6892, DIN 50125 and other standards, on metals, polymers, composites and geotextiles.

Start from the highest force your specimens reach. The NGSA304A is rated to 30 kN, the NGSA105A to 100 kN (22,481 lbf) and the NGSA305A to 300 kN, and all three take flat and round specimens of metal or composite.

The specimen limits are the same on all three: hardness below 30 HRC and tensile strength below 600 MPa. In each grip the pull drives the jaws in, so the clamping force rises with the load.

Size and weight grow with capacity, which matters when grips are changed by hand. Each upper or lower grip weighs 13.5 kg (30 lbs) at 30 kN, 15.3 kg (34 lbs) at 100 kN and 38.5 kg (85 lbs) at 300 kN.

The 300 kN grip is also 348 mm high and 538 mm wide overall, so check the room in your frame before choosing it.

The 30 kN and 100 kN grips take flat specimens up to 21 mm thick and round ones from Ø4 to Ø19 mm, and the 300 kN grip takes up to 32 mm and Ø30 mm. Each flat or vee face covers one band of sizes, and faces change without changing the grip body.

On the 30 kN and 100 kN grips the faces measure 50 × 40 mm with a 1.5 mm serration pitch. Flat faces come in three bands of 7 mm, and vee faces cover Ø4 to 9, Ø9 to 14 and Ø14 to 19 mm.

The 300 kN grip moves to larger 62 × 50 mm faces with a coarser 2.0 mm pitch. Its flat faces come in four bands of 8 mm, and its vee faces cover Ø4 to 9, Ø9 to 16, Ø16 to 23 and Ø23 to 30 mm.

The NGQA502A handles filament, the NGH203A glass fiber, cotton thread and nylon cord, and the NGB502B steel wire. In each, the specimen wraps around a drum before it reaches the jaw, so friction on the drum carries much of the load and the jaw holds only the remainder, which keeps the break away from the clamp.

The NGQA502A is pneumatic, so air closes it with the same pressure every time. It is rated to 500 N and takes specimens up to Ø1.5 mm.

The NGH203A works on the same principle by hand at up to 2 kN, for specimens below 500 tex. The NGB502B is rated to 500 N for steel wire up to Ø1.5 mm and holds it on a wave-profile jaw face of 36 × 10 mm.

More snubbing designs are on our snubbing grips for wire and cable page.

The NGSA102A, rated to 100 N, suits spandex and other non-metallic single wires up to Ø1.5 mm, and the NGSD503A, rated to 5 kN, suits textiles up to 14 mm thick.

The NGSA102A is the lightest grip in the series, for specimens that tear before they slip and need only a light hold. It has 10 × 10 mm jaw faces, and each grip weighs 0.4 kg and stands 75 mm high. Low grip weight matters on a low-capacity load cell, which carries the weight of the grip attached to it.

The NGSD503A clamps textiles on 95 × 35 mm wave-profile faces without damaging the fabric, and each grip weighs 1.73 kg (3.8 lbs).

Other side-action designs and capacities are on our side-action grips page.

Three compression fixtures cover the range, chosen by force and by how rigid the specimen is. For soft and flexible non-metallic materials, the NGC502A is rated to 500 N, and its 150 mm diameter gives a broad, stable base.

For concrete, metal and plastic at up to 20 kN, a compact fixture 100 mm in diameter keeps the setup short, with a 70 mm upper part and a 60 mm lower part.

At 100 kN, a fixture of the same diameter adds composites to the list and sits on a spherical seat. The seat lets the upper face settle onto a specimen whose ends are not quite parallel, which keeps the load on the axis.

Further designs for rigid samples are on our compression fixtures page.

The 100 kN fixture adjusts its span up to 360 mm and uses Ø20 mm loading and support rollers, while the 10 kN fixture spans up to 160 mm and carries both R5 mm and R2 mm rollers. Both run three-point tests on flat and round metallic specimens.

The larger fixture takes specimens up to 80 mm wide, and the smaller one up to 40 mm. On the smaller fixture the two roller radii let the setup follow the method and the thickness of the specimen.

In a three-point test the load acts at mid-span, so for a given force the bending moment grows with the span. An adjustable span lets one fixture test several specimen sizes at the spacing each method calls for.

Other three-point designs are on our 3-point bending fixtures page.

The series uses three pin sizes, Ø10, Ø18 and Ø28 mm, and the size follows the force rating because the pin carries the full test load between the fixture and the machine.

Nine of the thirteen items mount on Ø10 mm pins, from the 100 N side-action grip up to the 30 kN wedge grip, the 20 kN compression fixture and the 10 kN bending fixture. The three 100 kN items move to Ø18 mm pins: the wedge grip, the sphere-seated compression fixture and the larger bending fixture. The 300 kN wedge grip connects through Ø28 mm pins.

Every item is rated for ambient working temperature and fits NextGen universal testing machines. The series can be ordered with a new system or added to a machine already in the lab, and our technical sales team will configure the connections for the frame it runs on.