R-clips and cotter pins are fasteners inserted into pin holes in parts such as bolts and shafts to stop them from turning and prevent them from coming off. Cotter pins are opened and fastened in place after being inserted in the pin hole. They are non-reusable. R-clips are reusable parts that are easy to attach and remove. When selecting R-clips and cotter pins, the right size model for the hole of the bolt or shaft to be fastened should be chosen. The central part of the R shape in an R-clip should be equal in size to the radius of the hole for insertion. R-clips made of stainless steel has superior resistance to corrosion and heat, enabling use in humid locations or outdoors. Some R-clip products have bent tips that prevent removal. R-clips and cotter pins are both fasteners used to stop parts from turning. Cotter pins are used when the fastener must never come out, and R-clips when convenient fastener attachment and removal must be prioritized.