Correct specification callout for 440C passivation of stainless steel

A. Hi Sean. If your parts are neither orthopedic implants nor aerospace parts, then ASTM A967 will probably be a good spec for your parts.

That spec and others are available for instant downloading from the authoring body and from clearing houses. You should never call it out without seeing it though. One of the practical reasons is that such specs can obligate you, not just the vendor. For example, some time ago there was a huge fiasco of components fracturing in the field, with all the attendant costs & dangers, due to hydrogen embrittlement from electroplating. Why aren't all parts baked for embrittlement relief after plating? Because it costs money and is only required for hardened parts ... and a lot of parts (if not most) aren't hardened. Why didn't the plating shops know that the parts were hardened and required baking? Because according to the spec that caused the problem, it was not their job to do hardness testing, it was the buyer's job to notify the plating shop that the parts were hardened and required baking.

The spec you mentioned also includes options such as citric acid vs. nitric acid passivation. There may be a reason for your to specify one vs. the other for your specific parts. And hey, be careful out there :-)