... durable 2. Wear-resistant 3. Accord with GB6003.1-1997 standard and ISO3310-1:1990 R20/3,R20,R40/3 series ... Steel, H80 BrassStainless SteelStainless SteelProduction TechnologyWeavingPunchingElectrochemical machiningProduction StandardGB6003.1-1997 standard and ISO3310-1:1990 R20/3,R20,R40/3 seriesGB6003 ... .2-1997 standard and ISO3310-2:1990 R20/3,R20,R40/3 series ...