Quick release pins come in a variety of styles, one of the most popular being R-clip. Also known as hairpin cotters and R-pins, they are characterized by their shape resembling the letter R. One side is straight and the other is curved.
R-clip pins slide through a hole in a shaft to and hold parts securely in place with spring-like tension. They are commonly used in applications where parts need to be removed easily. Pulling the R-clip pin out of the shaft will release the parts. If you’re looking to buy an R-clip pin, however, there are several things you should consider.
Length
R-clip pins are available in different lengths. Some of them are long, whereas others are short. You should choose an R-clip pin that’s long enough to fit all the way through the hole with which you intend to use it. If it’s too short, the curved end won’t “lock” into place. As a result, the R-clip pin will sit loosely in the hole while subsequently failing to hold the parts together.
Wire Diameter
You should also consider the wire diameter when choosing an R-clip pin. The wire diameter represents the pin’s thickness. With a wide diameter, R-clip pins are typically stronger and more durable. But if the diameter is too wide, the R-clip may not fit. Therefore, you should choose an R-clip pin in a diameter that’s appropriate for the application. Make sure the wire diameter isn’t wider than the diameter of the hole.
Material
What material is the R-clip pin made of? Nearly all R-clip pins are made of metal wire, but the specific type of material from which they are made varies. Two of the most common materials for R-clip pins are stainless steel and spring steel. While they are both iron alloys with added carbon, they aren’t the same.
Spring steel has a higher carbon content than its stainless steel counterpart. It’s also more flexible and able to return to its original shape after deformation. Stainless steel, in comparison, has more chromium. The presence of this chromium enhances the pin’s corrosion resistance, making stainless steel R-clip pins popular for use in humid environments.
Surface Finish
Something else to consider when choosing an R-clip pin is the surface finish. Since they play a critical role in securing parts, R-clip pins often feature a protective coating or finish. Some of them have a vinyl surface finish. Other R-clip pins have a transparent or white zinc surface finish.