Astm A564 Pdf -

"17-4" is a nickname. The law is ASTM A564/A564M (Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars).

You order "17-4 Stainless." The mill sends "Condition A" (annealed). You try to machine it, and it’s gummy. 🥴 Because you forgot to specify the heat treat condition. astm a564 pdf

❌ Assuming "A564" guarantees magnetic permeability is low. (Hint: 17-4 is magnetic in H900). "17-4" is a nickname