Is the Paramilitary 2's stop pin made from a different steel?

[Lawrence]

I've noticed that the stop pin of the Paramilitary 2 corrodes more easily than the rest of the knife. Others have had this issue too. This is interesting, and I'm entertaining a few ideas as to why it happens. Perhaps the steel used is a different type that resists cracking from impact, but sacrifices corrosion resistance; or perhaps it is heat-treated differently and this allows it to rust somehow. It would be interesting to find out if anybody knows whether this is the case. Have Eric or Sal ever mentioned it in the design of the knife? Cheers. :)

[Brock O Lee]

Yes I have noticed this too. I had to remove rust from a PM2 stop pin before, but all the other hardware was unaffected. My guess is different steel or heat treat.

[MarcusH]

AFAIR the common material for the stop pin within the knife industry is hardened Grade 416 steel which sacrifices some corrosion resistance to a better machinability compared to other steels. It's a martensitic steel which is pretty strong and tough, the European norms would be 1.4005 and X12CrS13.
The screws of the Paramiltary most probably are made of some Grade 300 Series steel. This is a group of austenite steels which has a much better corrosion resistance compared to Grade 416 due to the much higher Chromium content.

[bearfacedkiller]

I don't know what steel it is but usually stop pins are hardened and standoffs are not.