... do OEM. 4.Wire dia.:0.1m10mm 5.Auto tool extension. Usually,we are very welcome customers' drawings and samples. ... want about the spring,please feel free to contact us. Extension Spring common specifications.1.Wire Dia.:0.1mm-10mm.2 ... Gold,Tin, Chromium, Yellow zinc,Oxide Black,Brass.5.Applications:Industrial,Medical applications, Automotive,Auto,Household appliances.Electronic products,Hardware tool.