1.diameter of spring wire from 0.5mm to 15mm 2.finish:anti-rust oil ,zinc,nickel,silver, ... :auto,motorcycle,industry 1.spring , hardware spring,cylinder spring, mechanical spring,mechanical spring reel,spring drive mechanism are all available.2.Applications ... ,ariculture,mine,furniture,elevator and so on6.wire diameter from0.5mm to 15mm7.High quality with competitive price mechanical spring