Metric Spring Pins

Metric Spring PinMetric spring pins provide extra security in parts of assemblies prone to frequent jolts or vibration. Ordinary dowel pins or other metric fasteners can respond to these disturbances by coming loose and eventually wiggling out of their shafts. A spring pin, however, produces some force of its own to counteract those outside forces. It actually exerts pressure radially, pushing against the walls of the shaft to keep itself securely in place.

There are two basic varieties of metric spring pins, coiled spring pins and slotted spring pins. Coiled spring pins are fashioned out of a flat strip of steel rolled into a cylinder so that if you look down at it from one end, you see a spiral pattern. How does this construction allow it to exert radial force outward into the shaft it’s driven into? Well, the pin’s diameter is actually slightly larger than the shaft — the ends have to be rounded or chamfered to help the pin force its way in.

Slotted spring pins exert the same kind of radial pressure as coiled spring pins, only without the coil. These pins are rolled out of sheet metal to give the appearance of an ordinary cylinder, but the edges of the roll don’t meet — a narrow longitudinal slot runs the length of the pin, so that viewed from one end it looks like a “C.” This tiny gap gives the pin just enough “springiness” to get the job done.

You’ll see metric spring pins used in all kinds of applications, especially in electrical and automotive components, from car door handles to computer memory ejector pins. Here at Mr. Metric we offer regular steel spring pins or stainless steel spring pins for corrosion-resistant performance. Whenever you need metric spring pins, Mr. Metric will spring into action to get them to you!

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