Mil-spec Hammer/Trigger Spring Material & Coating

[prepare]

Lately I have noticed a variation of hammer and trigger springs even from the same manufacturer/brand. Some are silver, some are black, others are sort of brownish.
What is the mil-spec material and coating supposed to be?

[lysander]

Lately I have noticed a variation of hammer and trigger springs even from the same manufacturer/brand. Some are silver, some are black, others are sort of brownish.
What is the mil-spec material and coating supposed to be?
You are certainly an inquisitive little . . . fellow, aren't you.

Well, since these two springs are made from stainless steel wire, they should be cleaned and passivated per SAE SMS2700 or ASTM A380 and ASTM A967.

Most all of the springs are made from either stainless steel (17-7PH, ASTM A313) or music wire (ASTM A228).

Stainless steel (finish passivated):
8448520
8448532
8448532
8448574
8448583
8448586
8448590
8448593
8448594
8448598
8448611
8448629
8448633
8448637
8448659
8448671
8448787
9349069
9349070
9349109
9349116
9390022
9390027
13021313

Music wire (finish not specified)
8448516
8448540
8448542
8448753
9349107
12951020
12999901
12972695

Other
8448536 - AISI 1095 - Parkerized
8448555 - AISI 1075 - Parkerized
12011987 - AISI 1095 - Parkerized

[prepare]

Thats from seeing so much inconsistency on the commercial side. These springs are just a small example.

[lysander]

May not be "inconsistency", there are many ways to passivate.