Stanley makes a variety of compression springs in concave and convex configurations, wire thickness range from .004 to .250”. Materials include hard drawn wire, music wire: zinc coated music wire, galvanized music wire, tinned music wire, preco-z music wire; stainless steel wire including: annealed stainless steel, 302 stainless steel, 316 stainless steel, 17/7 stainless steel, elgiloy wire, nichrome wire, nickel coated copper wire, oil tempered wire, and galvanized hard drawn wire. Loop types include open end ground, open end not ground, close end ground, close end not ground.