1020 1/4 hard steel

[fox9719]

My hardness testing was done by a metallurgist that I shipped a sample to.
I’m sure the test was done correcting.
Buying coil steel is all new to me. I was handed some old orders with the specs and had to get some material ASAP. I ordered a small amount from our current suppler to get us through till I understood better what I needed to be doing.
After some research and feedback from other suppliers I think that the specs are incorrect.
We ask for 1020 ¼ hard CRS. We also have C 20-26 in the spec. Is the C for carbon or hardness?
My current supplier did not know. So no help there. If it is for carbon it is not 1020 CRS.
If it refers to hardness it is not ¼ hard.
Any help will be greatly appreciated.
OUR specs..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

 

[metengr]

fox9719;
Have you searched ASTM for typical steel coil specifications?

Look at ASTM A 109. You will find all you need for ordering

Standard Specification for
Steel, Strip, Carbon (0.25 Maximum Percent), Cold-Rolled

 

[metengr]

By the way for 1/4 hard steel coil purchsed to A 109, the hardness is in Table 3

Rockwell B Hardness 60-75

 

[MetalGuy10]

Fox9719,

Metengr correctly noted that Astm A109 should be used for ordering purpose, but there are a couple of other minor issues you should note that will affect your order acceptance and availability. A109-08 has a max width of 23”. Your order width ( OUR specs..1020 CRS .023 +/- .003 X 1.875 +/- .005 X COIL) appears to be 1.875”. Most cold mills prefer to run coils as big, wide, and long as possible for maximizing production; typical mill widths are 36, 48, and 60”. The service center will typically buy from the mill with a different spec (A1008, A568), and then they slit to their customers final width and sell the material on the new spec such as A109. The spec A109 itself does not does not have a section for ordering material to a chemistry SAE grade spec like 1020, but the service center that works with the mills can let them know your chemistry aims. A568-09 has some SAE chemistry ranges, Table X2.1 that may be helpful.

I wasn’t sure of the actual hardness that your material had (“¼ HARD COIL C 20-26), but the hardness should be measured on the Rockwell hardness B scale, Rb. The Rockwell hardness C scale gets dicey below 20 HRC.

Your current supplier’s lack of product knowledge for their own customer (you) should concern you. I would ask your current supplier to give you all the mill test reports that they received when they purchased the material from the mill. The mill test report (MTR) will contain the ASTM spec, grade, actual chemistry, and mechanical properties if they were part of the spec requirements.

Since you are negotiating with new suppliers, you may want to send them samples from your “raw” coils for hardness test, tensile test, and a chemistry check evaluation. Sending a part or print to a potential supplier may help to ensure that you get what you need. Working with both old and new suppliers may also be a way for negotiating a better price.