WHAT IS "STRAW PASSIVATION"

A. Hi Sunjai. Your inquiry happens to be the fifth this week (and it's only Wednesday) that I can paraphrase this way: "My customer wants me to do xxxx, and I have no idea what he wants; so please tell me what he wants me to do because I'm afraid to ask, or the buyer is afraid to ask the designer".

I could hazard a guess that your customer wants the bolts zinc plated and for the chromate conversion coating on the bolts to be straw colored (yellow), Sunjai. But if you were to follow someone's guess rather than getting clarification, your customer is completely justified in rejecting the entire order. C'mon people, communication is key :-)

But these postings may remind specifiers that abandoning trusted sources in favor of new ones can sometimes be foolish. Good luck!

A. Hi Jamie. No, it's NOT a recognized industry term. Articles that are zinc plated (not just nuts & bolts) are invariably chromate conversion coated to deter white rust. The chromate conversion coating is sometimes called "chromate passivation" or "passivation of the plating". The chromate conversion coating can be clear, slightly bluish, yellowish, olive drab, or black. It appears that someone probably decided to call a yellowish chromate conversion coating "straw passivation". I would not use the term, and I would not try to comply with it without clarification from the customer. Best of luck.

Regards,

Contractors should never be afraid to ask for description of a process, or a copy of the referenced standard, or whatever they would need to do the job.

It works both ways, though. Buyers shouldn't really be sending out RFQs with vague requests. Call out the specific industry standard that applies or include a copy of the internal company standard.

We were recently discussing over in letter 12627 about the need to even be specific about the VERSION of the standard. That's as good an excuse as any to double check with the buyer on exactly what process they are asking for.