Friction Factor for Bolted Connections

Material

non-lubricated

lubricated

steel - steel

0.8

0.16

steel - cast iron

0.4

0.21

steel - brass

0.35

0.19

steel - brass

0.13

0.16

cast iron - cast iron

1

0.15 - 0.20

cast iron - bronze

0.25

0.08

bronze - bronze

0.25

0.10

aluminum - aluminum

1.35

0.30

copper - copper

1

0.08

steel - plexiglas

0.4 - 0.5

0.4 - 0.5

plexiglas - plexiglas

0.8

0.8