About Counterbores
Create flat-bottomed holes, so your screw heads sit flush, recessed, or slightly raised.
Reverse Counterbores
High-Speed Steel
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Counterbore Head  | 
Counterbores  | Required Shanks  | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Uncoated  | ||||||||||
Body Dia.  | Overall Lg.  | No. of Flutes  | Each  | Shank Dia.  | Overall Lg.  | Each  | ||||
| 5/16" | 1/2" | 4 | 0000000 | 000000 | 3/32" | 6" | 0000000 | 00000 | ||
| 5/16" | 1/2" | 4 | 0000000 | 00000 | 1/8" | 6" | 0000000 | 0000 | ||
| 5/16" | 1/2" | 4 | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 | ||
| 3/8" | 1/2" | 4 | 0000000 | 00000 | 1/8" | 6" | 0000000 | 0000 | ||
| 3/8" | 1/2" | 4 | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 | ||
| 3/8" | 1/2" | 4 | 0000000 | 00000 | 3/16" | 6" | 0000000 | 00000 | ||
| 1/2" | 1/2" | 4 | 0000000 | 00000 | 5/32" | 6" | 0000000 | 0000 | ||
| 1/2" | 1/2" | 4 | 0000000 | 00000 | 3/16" | 6" | 0000000 | 00000 | ||
| 1/2" | 1/2" | 4 | 0000000 | 00000 | 1/4" | 6" | 0000000 | 00000 | ||



























