Plating Friction

[digger200]

This must have been asked before but my search turns nothing up.
what would be the coefficient of friction for a bolted joint when all parts are plated , components, washer, nut & bolt. I usually use 0.2 for the slip between two uncoated steel parts but plated parts seem "slippery" although the zinc coating would probably yield? so the figure may be higher??
Thanks

 

[unclesyd]

Most zinc coatings tend to raise the coefficient of friction when it come to fasteners. A number widely used is 0.23, in other words one has to increase the torque slighly over the dry state.

What type zinc coating do you have, hot dipped, electrolytic, or mechanical?

 

[desertfox]

Hi digger

Try this site:-

http://www.roymech.co.uk/Useful_Tables/Tribology/co_of_frict.htm#coefficients

regards
desertfox

 

[digger200]

Thanks guys, yes I've seen Roymech's site.
We use electrolytic plating. The bright silver finish.

 

[CoryPad]

Any post treatment to the zinc plating, like a chromate conversion coating? If so, then the friction coefficient could be ~ 0.1. If not, then ~ 0.23 like unclesyd said is a good start.

Regards,

Cory

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