... main products are: bolts, screws, nuts, machine screws, plain washers, spring lock washe rs, wood screws, tapping screws, drilling screws,chipboard ... finishing, we provide: black oxide, zinc electroplating, phosphate, copper plating, mechanical galvanization, hot dip galvanization, Dacromet, and others. Our products are ... information about our company, you are welcome to visit us. SPRING LOCK WASHER