Quick view #4, ID=0.12", OD=0.28", THK=0.025" Flat Washers, Brass Brass: machinable, ductile, corrosion resistant, excellent electrical and thermal conductivity.The nominal diameter is the bolt size to use for this flat washer.Diameter (Nominal): #4Inside Diameter (Nominal): 0.12"Outside Diameter (Nominal): 0... $38.63 Compare