headed pin / straight / knurled
headed, straight, knurled
Offered with or without a head, Knurled Pins are available with either straight or helical knurls. Unlike a Straight Pin where retention is provided by the uniform interference between the pin and hole, knurled pins are designed to cut into the host. The displacement of the host material into the valleys of the knurls yields more frictional contact area between the pin and hole thus resulting in higher retention.
Straight knurls have lower insertion forces than helical knurls, offer resistance to turning within the assembly, but provide limited retention when axially loaded. Therefore, straight knurls are often recommended when the pin is used to transmit torque such as when used as an axle to rotate a wheel.