About Counterbores
Counterboring—Enlarge the top of an existing hole to create a cylindrical-shaped opening with a flat bottom that acts as a seat for the head of a screw or wood plug.
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Inch Size Drill-Point Counterbores
Drill and counterbore holes with enough clearance for socket head screws without changing tools. The longer the counterbore, the thicker the material it can drill.
For technical drawings and 3-D models, click on a part number.
Dia. | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| For Screw Size  | Body | Shank | Drill Tip | Overall Lg. | Max. Hole Drilling Dp. | Number of Flutes | For Use On | Each | |
Uncoated High-Speed Steel | |||||||||
| No. 5 | 0.220" | 1/4" | 0.138" | 1 7/32" | 0.25" | 2 | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 00000000 | 000000 |
| No. 6 | 0.242" | 1/4" | 0.15" | 1 7/32" | 0.25" | 2 | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 00000000 | 00000 |
Inch Size Drill-Point Counterbore Sets
Keep counterbores in various sizes on hand to drill and counterbore holes with enough clearance for socket head cap screws without changing tools. The longer the counterbore, the thicker the material it can drill.
Diameter | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sizes Included | Overall Length | Number of Pieces | Body | Shank | Drill Tip | Maximum Hole Drilling Depth | Number of Flutes | Shank Type | For Use On | Container Type | Each | |
Uncoated High-Speed Steel | ||||||||||||
| No. 5 No. 6 No. 8 No. 10 1/4" 5/16" 3/8" 7/16" 1/2" | 1 7/32" 1 7/32" 1 15/32" 1 1/2" 1 3/4" 1 15/16" 2 11/32" 2 1/2" 2 11/16" | 9 | 0.22" 0.242" 0.29" 0.332" 0.406" 0.49" 0.593" 0.687" 0.781" | 1/4" 1/4" 5/16" 5/16" 7/16" 1/2" 5/8" 5/8" 5/8" | 0.138" 0.15" 0.178" 0.2" 0.28" 0.34" 0.406" 0.468" 0.532" | 1/4" 1/4" 0.281" 0.312" 3/8" 3/8" 0.468" 1/2" 0.562" | 2 | Round | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | Plastic Case | 00000000 | 0000000 |