The Portable Rockwell metal hardness tester is based, as its name suggests, on the static Rockwell measuring principle where the penetration...

The Portable Rockwell metal hardness tester is based, as its name suggests, on the static Rockwell measuring principle where the penetration depths under a defined preload are measured before and after application of a large force. During measurements with the Portable Rockwell probe, a diamond cone indenter is forced into the test piece to be measured and then released back out of the material. The indentation depth of the diamond is continuously measured while the load is applied and released. From the indentation depths d1 and d2 recorded at two defined loads, the difference is calculated: Delta = d₂ – d₁. The difference Delta reflects the plastic deformation and therefore is a direct measure of the hardness of the material. The Portable Rockwell method covers a wide range of applications like hardness measurements on small, light, thin, walled or tubular test objects, but also large and heavy objects can be tested as long as the surface roughness and grain size are small enough.