Self Centering Spring (L) This item was sourced on www.MFG.com as one of the items in an RFQ in USA for Compression Springs The spring will be put in pairs, inserted on a .5 inch dowel pin. The pair of springs will work in opposite direction to act as a self centering mechanism. The weight of the hook to be centered is the load called out in the drawing. The hook is not to deflect from center by more than 5 degrees without further load, but needs to deflect 90 degrees under increasing load. I would assume material to be piano wire. Please ask questions, as springs are not something we do often. Thank you! Production of a Self Centering Spring (L) (Compression Springs). Please see drawing for all specifications. Part Part Number: 1427725169854 Material: Carbon Steel Material Grade: Technical Specifications Category:Compression Springs Dimensions0.0 x 0.45 inch Tolerance:0.001Annual Usage:2.0 Get quotes online for manufacturing services at MFG.com from machine shops, fabricators, job shops and contract manufacturers. MFG.com connects buyers and suppliers when the buyer has a need and the supplier has the right expertise and capacity. MFG.com analyzes all engineered parts and RFQs for improved manufacturability and to ensure quality and a quick quoting experience. Compression Springs: Compression springs are wound or coiled to oppose or absorb compression along their length. Compression springs can be wound in constant or variable pitch. Compression springs can be straight, conical or have variable diameters through their length.