ASTM A193-B8M, CLASS 2

[FastenerDude]

The ASTM A193-B8M, Class 2 spec calls out a solution anneal and cold drawn material. The cold work is what kicks up the tensile strength on this material. Is there a way to tell how deep the cold work goes in the material when it is cold drawn? I have a customer who wants to machine some B8M, Class 2 material but is afraid he will machine all of the cold work off of the bar (he would be machining about 1/2" off a side). I told him that I am not 100% sure but think that would be enough to remove the cold work applied during the drawing process. Is there a way to tell how deep the cold work is applied to this material during the drawing process?

Thanks,
Greg

Greg
System 22, Inc.

 

[TVP]

The short answer is no. It will depend on the initial bar diameter, how much reduction takes place place during cold drawing, the die angle used, etc. Having said that, machining 0.5" off a side (total of 1" of the OD) is quite a lot for this type of maerial. I suspect that the mechanical properties will be lower than the minimums specified in Table 2.

 

[EdStainless]

Very much no.
Does this spec require that samples be tested any particular way?
Must they be take mid-radius for example?
Think about it, If you took a standard (1/2") tensile bar from near the surface, considering the diameter of the ends this bar will have a center line that is about 3/8" - 1/2" in from the surface. This is still fairly close to the surface.
If I was taking more than 1/4" total off the OD I would want a tensile test at either the mid-radius or at the center of the bar so that I knew what I was ending up with.

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