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About Counterbores
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Create flat-bottomed holes, so your screw heads sit flush, recessed, or slightly raised.
Port Counterbores
Carbide-Tipped Steel
 |
MS33649 and SAE AS5202 |
The hardest and most wear-resistant counterbores we offer. These bits stay sharper at higher temperatures and faster speeds for the best performance on hard and abrasive materials.
Shank | Uncoated | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Thread Size | Series No. | Overall Lg. | Dia. | Lg. | Type | No. of Flutes | Pilot Lg. | Mil. Spec. | Mfr. | Each | |||
SAE AS5202 | |||||||||||||
| 3/8"-24 | NB-3 | 5 1/16" | 0.4995" | 2" | Round | 4 | 0.598" | MS33649 | TOSCO | 2144A11 | 0000000 | ||
| 7/16"-20 | NB-4 | 5 5/32" | 0.4995" | 2" | Round | 4 | 0.671" | MS33649 | TOSCO | 2144A12 | 000000 | ||
| 1/2"-20 | NB-5 | 5 5/32" | 0.4995" | 2" | Round | 4 | 0.671" | MS33649 | TOSCO | 2144A13 | 000000 | ||
| 9/16"-18 | NB-6 | 5 3/16" | 0.4995" | 2" | Round | 4 | 0.724" | MS33649 | TOSCO | 2144A14 | 000000 | ||
| 3/4"-16 | NB-8 | 5 5/16" | 0.4995" | 2" | Round | 4 | 0.849" | MS33649 | TOSCO | 2144A15 | 000000 | ||
