The Jacobs Taper (abbreviated JT) is commonly used to secure drill press chucks to an arbor.
| Taper |
Small End |
Big End |
Length |
|
mm |
inch |
mm |
inch |
mm |
inch |
| 0 |
5.80 |
0.2284 |
6.35 |
0.2500 |
11.11 |
0.4375 |
| 1 |
8.47 |
0.3334 |
9.75 |
0.3840 |
16.67 |
0.6563 |
| 2 |
12.39 |
0.4876 |
14.20 |
0.5590 |
22.23 |
0.8750 |
| 2 Short |
12.39 |
0.4876 |
13.94 |
0.5488 |
19.05 |
0.7500 |
| 2½ |
15.88 |
0.625 |
17.20 |
0.677 |
26.80 |
1.055 |
| 3 |
18.95 |
0.7461 |
20.60 |
0.8110 |
30.96 |
1.2188 |
| 4 |
26.34 |
1.0372 |
28.55 |
1.1240 |
42.07 |
1.6563 |
| 5 |
33.43 |
1.3161 |
35.89 |
1.4130 |
47.63 |
1.8750 |
| 6 |
15.85 |
0.6241 |
17.17 |
0.6760 |
25.40 |
1.0000 |
| 33 |
14.23 |
0.5604 |
15.85 |
0.6240 |
25.40 |
1.0000 |
