What effect does plating have on bolt torque values? 1

[bb3ii]

Hello all,

Does anyone have any information on the effect cadmium and galvanizing (hot dip) has on the torque values required to achieve the desired tension in A325 bolts?

 

[CoryPad]

Cadmium plating has a friction coefficient around 0.15-0.20.

Hot-dip galvanizing as-received is similar to bare steel - 0.20-0.40, therefore it needs a lubricant. Amount of lubricant dictates the friction reduction.

 

go to this site and all will be answered C:\LIBRARY\Fasteners\BOLTS AND TORQUE SPECS.htm