316L DP1 1

[geoffthehammer]

We have a component where we have specified 316L as the material for a pressing, the supplier has counter-specified the material as 316L DP1 in his quotation. Can anyone tell me what DP1 means?

 

[gr2vessels]

I have noticed in the Asian denominations the DP1, DP 2, 3...8, as grades of lean, medium and highly alloyed Duplex Stainless Steels, which have been recommeded in some cases as replacement for the basic Austenitics, perhaps some equivalency in corrosion resistance and increased strength of the Duplex. It also appears in Japanese suppliers lists for CRA tubing and piping.
Hope this helps,
Cheers,
gr2vessels

 

[EdStainless]

This is why you should specify alloys using UNS numbers.
S31603 is 316L, nothing else.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[stumpii]

I have also seen it used to describe the finish on sheet materials DP1 = Dull Polish 1 side.

 

[geoffthehammer]

Stumpii is on the right track, I have since discovered that it does mean (in this instance) Dull Polish 1 side, i.e. nothing to do with the grade of steel per se.
Thanks for the input.