Counterboring Drill Bits
Often called step drill bits, these drill and counterbore holes at the same time. After drilling and counterboring, tap the hole and install your fastener. The body diameter may decrease after multiple sharpenings.
For technical drawings and 3-D models, click on a part number.
Dia. | Lg. | |||||||
|---|---|---|---|---|---|---|---|---|
| For Screw Size  | Body | Step | Step | Overall | Point Angle | For Use On | Each | |
Uncoated High-Speed Steel | ||||||||
| No. 6 | 0.250" | 0.15" | 1/2" | 4" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 000000 |
| No. 8 | 0.290" | 0.178" | 1/2" | 4 1/4" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| No. 10 | 0.332" | 0.204" | 5/8" | 4 3/4" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| 1/4" | 0.406" | 0.281" | 11/16" | 5 1/4" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| 5/16" | 0.500" | 0.344" | 3/4" | 6" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| 3/8" | 0.594" | 0.406" | 7/8" | 7 1/8" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| 7/16" | 0.688" | 0.469" | 1" | 7 5/8" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 |
| 1/2" | 0.781" | 0.531" | 1" | 9 7/8" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 000000 |