ASTM E140 is the ASTM standard that gives conversion tables and equations relating Brinell, Vickers, Rockwell, superficial Rockwell, Knoop, Scleroscope and Leeb hardness for specific metals. The current edition is E140-26.
The tables cover named material groups, including non-austenitic steels, nickel alloys, cartridge brass, austenitic stainless steel plate and sheet, copper, alloyed white iron and wrought aluminum, with the conversion equations given in annexes. ASTM treats the conversions as approximate and valid only for the materials named, because alloy, grain structure and heat treatment all affect the relationship between scales. Conversions are best used where specification limits have been set by agreement or mandate, and converting measured test data should be avoided where possible.
Labs that test on more than one scale, for example with a Macro Vickers hardness tester alongside a Brinell tester, use E140 when a specification calls for a converted value. If you need help matching ASTM E140 requirements to your parts or setup, contact our team.
