The following is summarized from the American National Standard Keys and Keyways for Milling Cutters and Arbors ANSI/ASME B94.19-1997
Keyways for Milling Cutters and Arbors
Nominal Shaft (Arbor)
Keyseat Cutter
Hole Diameter |
Nominal Size
Square Key |
Cutter Hole & Keyway |
Hole and Keyway |
| C |
C |
D* |
H |
Corner Radius |
| Hole Dia. |
(Square) |
Max. |
Min. |
Min. |
Nom. |
| 1⁄2 |
3⁄32 |
0.106 |
0.099 |
0.5578 |
3⁄64 |
0.020 |
| 5⁄8 |
1⁄8 |
0.137 |
0.130 |
0.6985 |
1⁄16 |
1⁄32 |
| 3⁄4 |
1⁄8 |
0.137 |
0.130 |
0.8225 |
1⁄16 |
1⁄32 |
| 7⁄8 |
1⁄8 |
0.137 |
0.130 |
0.9475 |
1⁄16 |
1⁄32 |
| 1 |
1⁄4 |
0.262 |
0.255 |
1.1040 |
3⁄32 |
3⁄64 |
| 11⁄4 |
5⁄16 |
0.343 |
0.318 |
1.3850 |
1⁄8 |
1⁄16 |
| 11⁄2 |
3⁄8 |
0.410 |
0.385 |
1.6660 |
5⁄32 |
1⁄16 |
| 13⁄4 |
7⁄16 |
0.473 |
0.448 |
1.9480 |
3⁄16 |
1⁄16 |
| 2 |
1⁄2 |
0.535 |
0.510 |
2.1980 |
3⁄16 |
1⁄16 |
| 21⁄2 |
5⁄8 |
0.660 |
0.635 |
2.7330 |
7⁄32 |
1⁄16 |
| 3 |
3⁄4 |
0.785 |
0.760 |
3.2650 |
1⁄4 |
3⁄32 |
| 31⁄2 |
7⁄8 |
0.910 |
0.885 |
3.8900 |
3⁄8 |
3⁄32 |
| 4 |
1 |
1.035 |
1.010 |
4.3900 |
3⁄8 |
3⁄32 |
| 41⁄2 |
11⁄8 |
1.160 |
1.135 |
4.9530 |
7⁄16 |
1⁄8 |
| 5 |
11⁄4 |
1.285 |
1.260 |
5.5150 |
1⁄2 |
1⁄8 |
MILLING CUTTERS
*D maximum is allways .010" larger than D minimum.
All dimensions given in inches.
