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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Tight-Spot Reverse Counterbore Heads
Shown with Shank (Sold Separately)
Counterbore Head
If limited space makes it difficult to counterbore your hole, access it from the other side with one of these tools. Put the shank in your drill chuck, insert it into a through hole, and attach the counterbore head on the end. Pull back on the drill to counterbore the backside of the hole.
Shank (sold separately) is required. The shank diameter should match the diameter of your through hole.
For technical drawings and 3-D models, click on a part number.
Counterbore Heads | Required Shanks | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| For Hole Dia. | Body Dia. | Overall Lg. | For Use On | Each | Shank Dia. | Overall Lg. | Each | ||
Uncoated High-Speed Steel | |||||||||
| 3/32" | 5/16" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 000000 | 3/32" | 6" | 0000000 | 00000 |
| 1/8" | 5/16" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 1/8" | 6" | 0000000 | 0000 |
| 1/8" | 3/8" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 1/8" | 6" | 0000000 | 0000 |
| 5/32" | 5/16" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 |
| 5/32" | 3/8" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 |
| 5/32" | 1/2" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 |
| 3/16" | 3/8" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 3/16" | 6" | 0000000 | 00000 |
| 3/16" | 1/2" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 3/16" | 6" | 0000000 | 00000 |
| 1/4" | 1/2" | 1/2" | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 0000000 | 00000 | 1/4" | 6" | 0000000 | 00000 |