1020 1/4 hard steel

[fox9719]

I ordered steel to the specs below. The material i got checks full hard.Did I just get the wrong mat. or are my specs the problem?
1020 CRS .023 +/- .003 X 1.875 +/- .005 X COIL
¼ HARD COIL C 20-26
#2 FINISH # 3 EDGE SLIT
COIL SIZE: 20” ID X 28”-34” MAX OD
LIGHTLY OILED
GUARANTEED CAMBER MAX IS .250 IN ANY 8 FT. LENGTH

 

[MikeHalloran]

Material that thin requires special techniques for hardness measurement, to be sure you're not measuring the hardness of the machine's anvil right through the sample.

If you're using a non-"superficial" hardness scale, you'll probably see a witness mark right behind the indenter mark.



Mike Halloran
Pembroke Pines, FL, USA

 

[TVP]

Just to follow up on what Mike mentioned, ASTM E18 specifies the minimum thickness of the test piece based on hardness in Table A5.1. Specifically, for HRC 20, the minimum thickness is 0.040 inches (1.02 mm). Your test piece would need to be indented using HR45N and converted to HRC (see ASTM E18 Table A5.3 and conversions in ASTM E140).