Home /
Search 🔍
the Site

Free personalized metal finishing help!


(-----) February 13, 2008

Q. Good Day,
My name is Sunjai Harilall. I am from Johannesburg, South Africa. I have what I think is an interesting Question. I work for a bolt company. I have an enquiry for bolts and nuts that have to be "Straw Passivated" Does anybody know what type of plating this is. I have tried unsuccessfully to find out more on this plating, but no one in South Africa knows. Please help.

Sunjai Harilall
Buyer - Johannesburg, South Africa

February 13, 2008

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!

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

jamie burton January 16, 2015

Q. Is "straw passivation" a recognized industry term? What does the process involve? Does it just relate to nuts and bolts or a particular type of metal?

Jamie Burton
environmental - United kingdom

January 2015

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.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

January 20, 2015

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.

ray kremer
Ray Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois
stellar solutions banner

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2022 finishing.com, Pine Beach, New Jersey, USA