A tapered pin is a fastener used in mechanical engineering. They are steel rods with one end having a slightly larger diameter than the other. Standard inch-sized tapered pins have a taper on diameter of 1:48 while metric ones have a taper of 1:50. 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.
Some tapered pins have a male screw thread on the small end that holds the pin in place with a washer and a nut. Other pins are threaded on both ends, on the thick end to pull the pin out with the same nut that holds the pin in place.
- Machinery's Handbook
- Newnes Mechanical Engineer's Pocket Book