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Baking Confusion regarding Yellow Zinc Plating

Hi....we are currently yellow zinc plating a lot of our parts with the spec ASTM B633 Type II and there is a lot of confusion regarding the post bake operation. What amount of time should these parts be post baked for and at what temperature. Also what type of parts is this necessary for.....we coat a lot of hardware i.e., nuts and bolts....is the post bake required for these as well? Currently I believe our plater givers them 30 min....please advise

Richard Tickner
material coordinator - London, ON, Canada
March 13, 2008

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March 14, 2008

The requirement for a bake is mostly driven by the hardness of the part which equates to one of the strength measurements for steel.
30 Min is inadequate for hard parts, like high strength nuts and bolts.
The real requirement that is overlooked or poorly stated is to get the parts into the bake oven as quick as possible after plating. When I was in the business of Mil spec parts, we used 15 mins. as a max and we never had a failed notch bar test. We also limited the time in the acid etch tank to the minimum to do the job.

James Watts
- Navarre, Florida

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Richard

If your supplier is plating to ASTM B633, they should have a copy of it, and meeting the requirements. Your post seems to indicate they do not. Do you really want to business with them? If so, buy them a copy if they will not.

Willie Alexander
- Colorado Springs, Colorado
March 15, 2008