... From prototyping through production, we will help you with custom solutions for your compression, torsion and extension spring ... 0.15mm to 80mm.Finish: Chromium-plated, zinc-plated gold-plated, silver-plated, copper-plated, tin-plated and ... cameras, computers, power switches, architecture, furniture, locks, hardware and plastic moulds, sports equipment and toys. Engine valve spring (with gold finish)