Use SD-3 Counterbores to drill a pilot hole and counterbore a flat bottomed hole in one step. Perfect for lag screws, lag bolts, washer head screws, T-nuts & more.
- Drive Shank: 1/4 Inch Hex Power Bit Shank
- Drill Size: 1/8 Inch
- Counterbore Size: 3/8 Inch
- Drive Shank: 1/4 Inch Hex Power Bit Shank
- Drill Size: 1/8 Inch
- Counterbore Size: 3/8 Inch