Floor unit for hardness differences: two points soft means two HRC numbers under the minimum. Heat treaters talk tempering adjustments in points, since a given change in temper temperature moves a given steel by a fairly predictable number of them. In steel grades, points also means hundredths of a percent carbon, so a 40-point steel has 0.40 percent carbon.
They're two points over the print, retemper 50 degrees hotter and check again.
Also heard as
- Rockwell points
- points of carbon
Related terms
Rockwell hardness
The standard shop hardness test that presses a diamond or ball into a part and reads depth as a number.
Tempering
Reheating hardened steel below its lower critical temperature to trade some hardness for toughness.
Rehard
To harden a part again after it misses hardness, usually after normalizing or annealing it first.
Draw
Shop word for tempering, as in drawing hardened steel back to a softer, tougher hardness.