BOLT TORQUE COEFFICIENT K FACTOR TABLE

Torque coefficient k factor table for bolts.

Bolt Condition K
Nonplated, black finish  0.30
Zinc-plated 0.20
Lubricated 0.18
Cadmium-plated 0.16
Source : From Shigley's Mechanical Engineering Design [Ref 3] page 427

 

Reference:

  • Oberg.E , Jones.D.J., Holbrook L.H, Ryffel H.H., (2012) . Machinery's Handbook . 29th edition.  Industrial Press Inc. , pp 1521 - 1537
  • Budynas.R , Nisbett.K. (2008) . Shigley's Mechanical Engineering Design . 8th edition.  McGraw-Hill
  • Barrett T.R. (1990), NASA - RP - 1228, Fastener Design Manual