Tapered_pin
Taper pin
Fastener consisting of a steep conical rod which is forced into a hole
A taper pin is a fastener used in mechanical engineering. They are steel rods with one end having a slightly larger diameter than the other.
Metric taper pins have a taper of 1:50.[1] A 1:50 taper means that one end of a 50 mm long bar will be 1 mm smaller in diameter than the other end. Inch-sized taper pins have a slightly smaller taper taper on diameter of 1:48[2] A 1:48 taper means that one end of a 4-foot-long bar (48 inches) will be 1 inch smaller in diameter than the other end, or a 1⁄4-inch taper over a 1-foot length.