What is exactly CFS?

[unp1]

Could any one please tell me what is CFS?

I submitted a PPAP for a screw machine part and the customer rejected it. The reason for rejection is, the material on the drawing is CFS and I used 12L14. They are saying that material cert doezn't match the spec. I think CFS is a very broad range and we can use any steel as long as it is cold worked, right?

Thanks.

 

[CoryPad]

Maybe CFS means Cold Forged Steel. Since you used 12L14 and screwed machining, you don't match the design intent.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[unclesyd]

Adding a little to CoryPad'spost, the 12L14 bar is cold drawn product. Leaded CS steels can be drawn with relatively few problems but several problems arise when you try to cold forge it.
I would change the print to to allow the 12L14 material as it's one of the best, fastest, for screw machine parts.

 

[TVP]

You should find out if CFS means Cold Forged (or Formed) Steel, or if it means Cold Finished Steel. If it is the former, then 12L14 obviously doesn't meet the requirement.