Source: http://en.wikipedia.org/wiki/Friction_coefficient#Coefficient_of_friction

MaterialsStatic friction, \mu_s\,
Dry and cleanLubricated
AluminiumSteel 0.61  
CopperSteel 0.53  
BrassSteel 0.51  
Cast ironCopper 1.05  
Cast ironZinc 0.85  
ConcreteRubber 1.0 0.30
ConcreteWood 0.62  
CopperGlass 0.68  
GlassGlass 0.94  
MetalWood 0.4 0.2
PolyetheneSteel 0.2 0.2
SteelSteel 0.80 0.16
SteelPTFE (Teflon) 0.04 0.04
PTFE (Teflon)PTFE (Teflon) 0.04 0.04
WoodWood 0.35 0.2