deal copper washers: material:copper,bronze,steel,brass etc. size:m5,m6,m8,m10,m12,1/ ... high pressure resistance, applicable to super low temperature. The copper washer is used in machinery fields. It has a good thermal ... content is more than 99.0%, and we dealing our washer with annealing and acid cleaning processes, the hardness is no ... (as the picture show), or 100pcs/box. high quality copper washer