Friktionskoefficient olika material

Friction force develops between contacting surfaces of two bodies and acts to resist relative motion between the bodies. The friction force, F, is proportional to the normal force, N, and the coefficient of friction, μ:

where μ_s is the coefficient of static friction and μ_k is the coefficient of kinetic friction. The value of μ_s is generally higher than the value of μ_k for a given combination of materials.

Coefficients of friction between materials are best determined through testing. However, it is possible to find tables in the literature for friction coefficients between various materials. We have collected some of those tables here.

The table below is from Barrett, "Fastener Design Manual," NASA Reference Publication ,

Materials	Static		Sliding
	Dry	Greasy	Dry	Greasy
Hard steel on hard steel		(a)		(k)
		(b)		(e)
		(c)		(i)
		(d)		(j)
		(p)		(d)
		(h)		(k)
				(l)
				(m)
				(a)
Mild steel on mild stee Coefficient of Friction Equation and Table Chart Design Resources Friction Design Data The frictional force for Static Friction can be expressed as: Fmax= μ Fn where Fmax= Frictional force (N, lb) μ = static (μ s ) or kinetic (μ k ) frictional coefficient Fn = Applied Normal force (N, lb) The frictional force for Dynamic Friction can be expressed as: For an object pulled or pushed horizontally, the normal force - N - is simply the vikt : N = m g Where: m = Mass (kg, slugs ) g = Gravity ( m/s2 , 32 ft/s2) Material Against Material Static Coefficient of Friction Dry Contact Lubricated Contact Aluminum-Bronze Alloy Steel - Brass Cast Iron Bronze Cast Iron - Bronze Sintered Steel -   Cadmium Chromium (Chrome) Cadmium Steel, Mild Carbon Carbon - Carbon Steel - Cast Iron Cast Iron Cast Iron Copper - Cast Iron Oak Wood Cast Iron Zinc - Colbalt (70°C) Cobalt .3 - Concrete Rubber (wet) Concrete Wood -