Hardness Tester

Selection criteria

Scale (HRC / HV / HB), load accuracy.

Supply chain

Hardness testers are widely available from international and Chinese instrument makers at many price points. Ensure the tester is calibrated with certified blocks and suits the scale required (HRC, HV, HB, Webster for aluminium).

Buyer FAQ

Which hardness scale should I use: HRC, HB or HV?

Use HRC for hardened steel (about 20–70 HRC), HB for castings and quenched-and-tempered forgings, and HV or micro-HV for thin layers and induction-hardened case-depth profiles. Aluminium is checked with HB, HRE/HRF or a Webster gauge. As a rule, the part must be at least 10 times thicker than the indentation depth.

How accurate should a hardness tester be, and how is it calibrated?

A Rockwell tester should read certified test blocks within roughly ±1–1.5 HRC, as allowed by ISO 6508-2 and ASTM E18. Check it daily or at each shift start with a block close to the expected hardness, and have an accredited lab perform indirect verification at least once a year.

What are common pitfalls when testing shafts and small parts?

Curved surfaces read low, so use a V-anvil and apply the cylinder correction from ISO 6508-1 on small diameters. Prepare a flat, scale-free spot and keep indentations at least 2.5 diameters from edges and from each other. Portable Leeb testers are convenient for large parts, but their converted values are only approximate.

Where it is used