Never Seize and torque values - Surprising results

[scottm]

My Machinery's Handbook has many pages of charts and formulas on the subject. Regarding the table on coefficients of friction: "Dry threads, indicated by the words "None added" in the Lubricant column, are assumed to have some residual machine oil lubrication. Table 1 values are not valid for threads that have been cleaned to remove all traces of lubrication because the coeeficient of friction of these threads may be very much higher unless a plating or other film is acting as a lubricant". There is no row for unplated fasteners with no lube added. I'm not sure if our lug nut threads are originally plated or not, and if so, how much is left?

Coefficients of Friction:
Steel, graphite lube: 0.07
Steel, moly grease: 0.11
Steel, machine oil: 0.15
Steel, cadmium plated, no lube: 0.12
Steel, zinc plated, no lube: 0.17
Steel to bronze: 0.15

I don't have my Bosch Automotive Handbook handy, I wonder what I'll find there?

I don't know if airplane manufacturers clean each fastener before assembly. I know automotive doesn't, I have to design the machines that feed and install fasteners. The oils build up and get messy. It's possible automotive designers spec a torque for tire shops that's different than they use in the factory for new lug bolts/nuts with oil film, I guess we could speculate a long time on that. I assume the factory assembles with machine oil on all surfaces, including under the head.