Letter 3082

ANTI-GALLING COATING 

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I AM LOOKING FOR A COATING TO USE ON A VARIETY OF THREADED STAINLESS STEEL PARTS TO PREVENT GALLING. THE PARTS ARE DISASSAMBLED/REASSEMBLED IN THE FIELD ON A REGULAR BASIS FOR REBUILDING AND CLEANING. CAN YOU SUGGEST A COATING OR PLATING THAT WE CAN HAVE APPLIED TO PREVENT THIS FROM HAPPENING?

MIKE RUFENACHT
GRACO - MINNEAPOLIS, MN

Teer Coatings in England has a graphite-based PVD coating that might fit the bill. I think they market it in the U.S. through Multi-Arc.

Jim Treglio
- San Diego, California

One of your best options is Electroless Nickel. It prevents galling, you could also use ENi with Teflon so that assembly/disassembly will be easier to perform.

Enrique Segovia
- Monterrey, N.L.

Silver is the standards non-galling coating for the vacuum technology business. Silver coated bolts are standard items. Don Mattox

Donald M. Mattox Society of Vacuum Coaters Albuquerque, NM   Ed. note:             Mr. Mattox is             the author of --

I used to use a chromium plating called ARMOLOY NTDC where I worked previously. Armoloy is an American company (Philadelphia I think). The coating is extremely hard, (about 70HRC / 1100HV), satin in appearance, and works wonders. In our experience it adhered and lasted much better than either Nickel or Silver. We used it for Nuclear applications mainly, where exfoliation of Nickel had been a problem.

Wayne Ward
- England

Carpenter Steel makes an austenitic stainless steel called 'Gall Tough' which works well. There is a competitors product called 'Nitronic 60'

Steve Cassidy
- Hudson, MA

If silver plating is not used, there are lots of different dry film lubricants, which are affordable solutions, particularily the ones that come in a spray can and do not have to be baked. They are not as good as baked, but would work fine for a touch up.

James Watts
- Navarre, Florida

Mike - Another anti-gall coating is manganese phosphate. It also holds an RP oil very well for corrosion protection. The production process is similar to zinc phoz. Ask your chemical vendor for info.

Dan Brewer
chemical process supplier - Gurnee, Illinois

I NEED TO CROSS REFERENCE THE SPEC BELOW PLEASE HELP? ANTI- GALLING COMPOUND PER PWA-36545-1

Laszlo Kocsis
- Tullytown, PA