1.Double-Spring-Washer; 2.Mm3-Mm64; 3.Plain&BLACK&WZP&YZP&BZP& ... ;6.material:carbon steel(incude A3#,34#,45#,etc,),brass;stainless steel;7.finished:smoothening(plain),galvanizing,yellow zinc plating,white ... .surface:hot treatment;10.our main products include flat washer,spring washer,metal washer,etc;11.competive price for FOB or ... any quality problem we pay for the loss at once; Double Spring Washer