Friction coefficients of various materials (per Ian)

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davesisk
Posts: 24
Joined: Tue Nov 02, 2010 7:53 am

Friction coefficients of various materials (per Ian)

Post by davesisk »

This is worthy of being a separate thread...can threads be made sticky here?

Friction coefficient of material against material:
Aluminium - Aluminium 1.35
Aluminium - Steel .61
Cast Iron - Steel .23
Cast Iron - Cast Iron .15
Teflon (piston rings) - Steel .04

This list is compliments of Ian S C (originally posted on another thread). I'll assume these are coefficients of sliding friction, not coefficients of static friction.

Cheers,
Dave
davesisk
Posts: 24
Joined: Tue Nov 02, 2010 7:53 am

Re: Friction coefficients of various materials (per Ian)

Post by davesisk »

Here's a great chart with lots of other material combinations. Note that the 2nd number with a superscript "1" is the coefficient of sliding friction if it's drastically different from the coefficient of static friction.

http://www.engineeringtoolbox.com/frict ... d_778.html

Frictional Coefficients for some Common Materials and Materials Combinations
Materials and Material Combinations Static Frictional Coefficient - μs Clean and Dry Surfaces Lubricated and Greasy Surfaces
Aluminum Aluminum 1.05 - 1.35 0.3
Aluminum-bronze Steel 0.45
Aluminum Mild Steel 0.61
Brake material Cast iron 0.4
Brake material Cast iron (wet) 0.2
Brass Steel 0.35 0.19
Brass Cast Iron 0.31)
Brick Wood 0.6
Bronze Steel 0.16
Bronze Cast Iron 0.221)
Bronze - sintered Steel 0.13
Cadmium Cadmium 0.5 0.05
Cadmium Chromium 0.41 0.34
Cadmium Mild Steel 0.461)
Cast Iron Cast Iron 1.1, 0.151) 0.071)
Cast Iron Oak 0.491) 0.0751
Cast iron Mild Steel 0.4, 0.231) 0.21, 0.1331)
Carbon (hard) Carbon 0.16 0.12 - 0.14
Carbon Steel 0.14 0.11 - 0.14
Chromium Chromium 0.41 0.34
Copper-Lead alloy Steel 0.22
Copper Copper 1 0.08
Copper Cast Iron 1.05, 0.291)
Copper Mild Steel 0.53, 0.361) 0.181)
Diamond Diamond 0.1 0.05 - 0.1
Diamond Metal 0.1 - 0.15 0.1
Glass Glass 0.9 - 1.0, 0.41) 0.1 - 0.6,
0.09-0.121)
Glass Metal 0.5 - 0.7 0.2 - 0.3
Glass Nickel 0.78 0.56
Graphite Steel 0.1 0.1
Graphite Graphite (in vacuum) 0.5 - 0.8
Graphite Graphite 0.1 0.1
Ice Wood 0.05
Iron Iron 1.0 0.15 - 0.20
Lead Cast Iron 0.431)
Leather Oak 0.61, 0521
Leather Metal 0.4 0.2
Leather Wood 0.3 - 0.4
Leather Clean Metal 0.6
Leather fiber Cast iron 0.31
Leather fiber Aluminum 0.30
Magnesium Magnesium 0.6 0.08
Nickel Nickel 0.7 - 1.1,
0.531) 0.28, 0.121)
Nickel Mild Steel 0.641) 0.1781)
Nylon Nylon 0.15 - 0.25
Oak Oak (parallel grain) 0.62, 0.481)
Oak Oak (cross grain) 0.54, 0.321 0.0721
Paper Cast Iron 0.20
Phosphor-bronze Steel 0.35
Platinum Platinum 1.2 0.25
Plexiglas Plexiglas 0.8 0.8
Plexiglas Steel 0.4-0.5 0.4 - 0.5
Polystyrene Polystyrene 0.5 0.5
Polystyrene Steel 0.3-0.35 0.3 - 0.35
Polythene Steel 0.2 0.2
Polystyrene Polystyrene 0.5 0.5
Rubber Cardboard 0.5 - 0.8
Rubber Dry Asphalt 0.9 (0.5 - 0.8)1)
Rubber Wet Asphalt 0.25 - 0.751)
Rubber Dry Concrete 0.6 - 0.851)
Rubber Wet Concrete 0.45 - 0.751)
Silver Silver 1.4 0.55
Sapphire Sapphire 0.2 0.2
Silver Silver 1.4 0.55
Steel Steel 0.8 0.16
Straw Fiber Cast Iron 0.26
Straw Fiber Aluminum 0.27
Tarred fiber Cast Iron 0.15
Tarred fiber Aluminum 0.18
Teflon Teflon 0.04 0.04, 0.041)
Teflon Steel 0.04 0.04
Tungsten Carbide Steel 0.4-0.6 0.1 - 0.2
Tungsten Carbide Tungsten Carbide 0.2 - 0.25 0.12
Tungsten Carbide Copper 0.35
Tungsten Carbide Iron 0.8
Teflon Teflon 0.04 0.04
Tin Cast Iron 0.321)
Tire, dry Road, dry 1
Tire, wet Road, wet 0.2
Wood Clean Wood 0.25 - 0.5
Wood Wet Wood 0.2
Wood Clean Metal 0.2 - 0.6
Wood Wet Metals 0.2
Wood Concrete 0.62
Wood Brick 0.6
Wet snow 0.14, 0.11)
Wood - waxed Dry snow 0.041)
Zinc Cast Iron 0.85, 0.211)
Zinc Zinc 0.6 0.04

1) Kinetic or sliding frictional coefficient - holds only when there is a relative motion between the surfaces; otherwise they are somewhat higher
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