Where the
world gathers for metal finishing
Q&As since 1989


-----

What is Electrolytic Zinc Plating per QQ Z 325 Type II standard?

2007

Hello

We are basically component manufacturing company situated in Chennai India. We have received an enquiry from an overseas company to finish their component as per the above mentioned standard. We are trying to do the same . We have this doubt whether the regular plating of Zn with Yellow passivation is similar to this spec.

Regards

Radhakrishnan
Mfgrs. of precision Machined Parts - Chennai, Tamilnadu, India

---

First of two simultaneous responses --

QQ-Z-325C ZINC COATING, ELECTRODEPOSITED (1976) is an old Federal Specification (U.S.), superseded in 1982 by ASTM B633. QQ-Z-325C is still available from ASSIST & standards vendors.

Type II indicates a chromating treatment capable of passing 96 hours salt spray testing per ASTM B117 without the appearance of white rust or base metal corrosion. A range of colors (bronze, brown, yellow, olive drab, etc.) is allowed; check with your customer if yellow is desired.
The zinc plating thickness must be specified: Classes 1, 2 & 3 correspond to 25, 13 & 5 micron, respectively. There are additional requirements, e.g., for plating on high strength steels. Get the spec.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2007

---

Second of two simultaneous responses -- 2007

While QQ-Z-325 was canceled 25 years ago and superseded by ASTM B633, Revision C is still available on ASSIST Quicksearch. Go there, download the document, and you'll see that Type II is chromate conversion coated.

Good luck!

Lee Gearhart
metallurgist - E. Aurora, New York

---

2007

Lee, is ASSIST still there? I have a user name and a password, but for some time now can't even get as far as using either - it's always "gateway error" or "gateway timeout" and there's no way around it. Can't get help from them about the problem, either, because even the base URL gives the same errors so they're totally uncontactable. Any thoughts?

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.

---

2007

Two possibilities, Bill. The first is that the URL changed. We keep it current on our Mil Specs FAQ because it has changed at least three or four times and people often have an old address.

The second (unlikely) possibility is that they figured a way to block access from outside of the USA.

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

---

2007

Bill,

The site is still accessible from out side of the USA, or should I say that it is available from the UK at least. If you are having trouble then try this address, it was working this morning (8-00am GMT):
http://assist.daps.dla.mil/quicksearch/

Hope your able to get back on line soon, the site is invaluable to anyone in this industry.

Brian Terry
Aerospace - Yeovil, Somerset, UK

---

Thanks guys - back on line to them now.

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2007