Tinius Olsen
Rockwell
Rockwell (HR scales) Indenting the test material with a diamond cone (HRC) or hardened (tungsten) steel ball indenter (HRB etc.). Applying a preload of 10kgf first and a main test force of 60, 100 or 150kgf.
Rockwell Superficial (HR scales) Indenting the test material with a diamond cone or hardened (tungsten) steel ball indenter, depending on the scale preliminary set. The Superficial Rockwell scales use lower force and shallower impressions on brittle and very thin materials. Applying a preload of 3kgf first and a main
test force of 15, 30 or 45kgf.
