... Steel Clutch Spring 1:precision clutch spring, offering OEM Service 2:MOQ:1000PCS 3:Dia:0.1mm-4.5mm 4:ISO9001:2008 Stainless Steel ... ), bronze, copper, phosphorus copper, beryllium copper. Alloy steel has 60Si2MNA, 60Si2CRVA, 55CrSiSurface treatment plate gold, silver, white, red yellow, blue, green, purple ... % balance remitted when see the copy of B/L Stainless Steel Clutch Spring