P Number

An internet search of "316L" produced almost 5 million results.

Could you describe exactly what the P (part?) number relates to? Is it relating to a metal, perhaps stainless steel in which case the 316L could be the grade of stainless steel the part(?) is made of.

is it (P/M) 316L you are talking about? just so you know 316L has less carbon than 316. half the amount.

P nos and group nos are available in Sec IX of ASME for most of the plate, sheet, pipe, tube, casting, forging, bar etc. and shown under QW 422- Grouping of Base Metals for Qualifaiction

316L has many specifications. For example,

If it is a Forging , then it should be SA-182 Type F316L

If it is a smls tube, then it should be SA-213 Type 316L

If it is a Plate, sheet, strip, then it should be SA-240 Type 316L

If it is a welded pipe, then it should be SA-332 Type TP316L

If it is a Fusion welded pipe, then it should be SA-358 Type 316L and like wise.

All the above types including bars, castings falls under P1 Group1.

sridhar.