... Assurance 3.Long Service Life 4.Good Hardness 5.Part name:Retractable Compression Spring Product scope Compression Spring, ... ranging from 0.1mm to 20mmProcess Stamping, bending, welding, casting, punching, machingSurface treatment Powder coating, zinc plated, nickel- ... , textile machines, high-low pressure switch springs, valve springs, safety valve mould springs, and chemical industry machines, as well ...