Extension Springs Available from stock or made-to-order Stock carried in 3 foot lengths will be cut to any free length needed and still shipped the same day. Other spring manufacturers have only standard sizes available from stock. Initial tension to order Regular machine hooks or loops Crossover hooks or loops Extended hooks Swivel hooks Plug ends Military Standard on hand Plating available upon request at a sister company for fast turn around Extension Spring Overview Extension Springs are most well known as the old fashioned "screened door spring". Their purpose is to extend out (such as when you open the screened door) and then to snap it closed when you are either outside or inside of the door. Extension Spring Specifications Free Length: 1 coil and up Diameter: 3/32" to 18" Wire Diameter: .005" to 2.00" Direction of Helix: LH or RH End Configuration: Machine Hooks, Crossover Hooks, Half Hooks, Extended Hooks Material: Over 35 alloys, such as: Music Wire, Oil Tempered Wire, Stainless Steel, Chrome Silicon, Chrome Vanadium, Elgiloy(R), Hastelloy(R), Inconel(R), Monel(R), Red Metals. >> Click here for the full material list. Extension Spring Applications The most common household application for exension springs is on screened front doors. Extension springs can also be found on most trampoline designs, which are usually lined with dozens of extension springs. Extension springs are also found in pinball machines, carburetors, vise-grip pliers and many other applications. Typical Uses Valve & Pipe Fittings Surgical & Medical Instruments Railroad Equipment Manufacturers Electronic Connector Manufacturers Electronic Components NEC Lamp Manufacturers Electric Industrial Valves Gaskets, Packets & Sealings Wiring Devices-Cur. Carrying Compressor Manufacturers, Air & Gas Measurement & Control Development Environmental Control Manufacturers Manufacturing Industries NEC Steel Springs except Wire Machinery Non-Electrical NEC Welding Apparatus Mills, Drawing & Insulating Industrial Machine Equipment Dealers Industrial Supply Whls. Switchgear & Switchboard Apparatus Steel Spring Manufacturers Measurement & Control Development Manufacturers Printing Trades machinery Oil Field Machine Manufacturers Custom Extension Spring Design The one draw back to an extension spring is that if you so desired, you could keep on pulling on the extension spring until you pulled it out and it was useless. If this is the case, Hardware Products Company can design a compression spring and then put tension ends on it so that you will only be able to pull the spring so much and the compression spring will go solid and the spring will not be able to be pulled out any further. >> Click here to learn more about Custom Extension Spring Design View Stock Extension Springs Request A Quote!