SCREW NUT COLLAR FRICTION TABLE

Collar friction and screw & nut friction table for lead screws.

Friction Coefficient [f] for Screw and Nut
Screw Material Nut Material
Steel Bronze Brass Cast Iron
Steel, dry 0.15-0.25 0.15-0.23 0.15-0.19 0.15-0.25
Steel, machine oil 0.11-0.17 0.10-0.16 0.10-0.15 0.11-0.17
Bronze 0.08-0.12 0.04-0.06 - 0.06-0.09
Source : From Shigley's Mechanical Engineering Design [Ref 1] and Mechanical Design and Systems Handbook [Ref 2]


Thrust-Collar Friction [fc] Coefficients
Combination Running Starting
Soft steel on cast iron 0.12 0.17
Hard steel on cast iron 0.09 0.15
Soft steel on bronze 0.08 0.10
Hard steel on bronze 0.06 0.08
Source : From Shigley's Mechanical Engineering Design [Ref 1] and Mechanical Design and Systems Handbook [Ref 2]

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