Taper pins are a very old and simple pin design. A Taper Pin is a steel rod with one end having a slightly larger diameter than the other. Standard inch-sized taper pins have a taper diameter of 1:48 while metric ones have a taper of 1:50. For a 1:48 taper, one end of a 4-foot rod (48”) will be 1 inch smaller in diameter than the other end ( 1⁄4-inch taper over a 1-foot length). A 1:50 taper means that one end of a half-meter rod (50 cm) will be 1 cm smaller in diameter than the other end.
Used for both fastening or locating Taper pins are, easy to install, reliable and very cost effective. Taper pins have a machined finish to increase the friction that holds everything together. Taper pins are widely used for pumps, in oil and gas applications. They also have applications in some electronics, ship building and the aerospace industry. A variety of materials, depending on the application, can be used to prevent corrosion or to specifically meet the demands for locating or fastening.
Standard lengths range for ½” to 7″
| Pin Size Number and Basic Pin Diameter | A | R | |||||||
| Major Diameter (Large End) | End Crown Radius | ||||||||
| Commercial Class | Precision Class | ||||||||
| Max | Min | Max | Min | Max | Min | Major Dia. | Approx. Fract. | ||
| 7/0 | 0.0625 | 0.0638 | 0.0618 | 0.0635 | 0.0625 | 0.072 | 0.052 | 0.0625 | 16-Jan |
| 6/0 | 0.078 | 0.0793 | 0.0773 | 0.079 | 0.078 | 0.088 | 0.068 | 0.078 | May-64 |
| 5/0 | 0.094 | 0.0953 | 0.0933 | 0.095 | 0.094 | 0.104 | 0.084 | 0.094 | Mar-32 |
| 4/0 | 0.109 | 0.1103 | 0.1083 | 0.11 | 0.109 | 0.119 | 0.099 | 0.109 | Jul-64 |
| 3/0 | 0.125 | 0.1263 | 0.1243 | 0.126 | 0.125 | 0.135 | 0.115 | 0.125 | 8-Jul |
| 2/0 | 0.141 | 0.1423 | 0.1403 | 0.142 | 0.141 | 0.151 | 0.131 | 0.141 | Sep-64 |
| 0 | 0.156 | 0.1573 | 0.1553 | 0.157 | 0.156 | 0.166 | 0.146 | 0.156 | May-32 |
| 1 | 0.172 | 0.1733 | 0.1713 | 0.173 | 0.172 | 0.182 | 0.162 | 0.172 | Nov-64 |
| 2 | 0.193 | 0.1943 | 0.1923 | 0.194 | 0.193 | 0.203 | 0.183 | 0.193 | 16-Mar |
| 3 | 0.219 | 0.2203 | 0.2183 | 0.22 | 0.219 | 0.229 | 0.209 | 0.219 | Jul-32 |
| 4 | 0.25 | 0.2513 | 0.2493 | 0.251 | 0.25 | 0.26 | 0.24 | 0.25 | 4-Jan |
| 5 | 0.289 | 0.2903 | 0.2883 | 0.29 | 0.289 | 0.299 | 0.279 | 0.289 | 19/64 |
| 6 | 0.341 | 0.3423 | 0.3403 | 0.342 | 0.341 | 0.351 | 0.331 | 0.341 | Sep-32 |
| 7 | 0.409 | 0.4103 | 0.4083 | 0.41 | 0.409 | 0.419 | 0.399 | 0.409 | 13/32 |
| 8 | 0.492 | 0.4933 | 0.4913 | 0.493 | 0.492 | 0.502 | 0.482 | 0.492 | 2-Jan |
| 9 | 0.591 | 0.5923 | 0.5903 | 0.592 | 0.591 | 0.601 | 0.581 | 0.591 | 19/32 |
| 10 | 0.706 | 0.7073 | 0.7053 | 0.707 | 0.706 | 0.716 | 0.696 | 0.706 | 23/32 |
| 11 | 0.86 | 0.8613 | 0.8593 | …. | …. | 0.87 | 0.85 | 0.86 | 55/64 |
| 12 | 1.032 | 1.0333 | 1.0313 | …. | …. | 1.042 | 1.002 | 1.032 | 1 1/32 |
| 13 | 1.241 | 1.2423 | 1.2403 | …. | …. | 1.251 | 1.231 | 1.241 | 1 15/64 |
| 14 | 1.523 | 1.5243 | 1.5223 | …. | …. | 1.531 | 1.511 | 1.5 | |