AISI 440C stainless steel balls Q/NBOY 1-2004 (SSZBM standard) Shanghai company's standard GB 308-2002 Chinese standard ISO 3290-1998 International standard Strict quality control, Unique workmanship. ZG products, Superior brand, top rank. Bearing balls diameter series Diameter Kg per 1000pcs No. of balls per kg inch mm 1/16 1.5875 0.016 62350 2.0000 0.0326 30700