Features High Hardness and Long Service Life: Overall heat treatment ensures high hardness, providing long-lasting durability for woodworking projects. Efficient Wood Chip Discharge: U-shaped chip grooves enhance drilling efficiency by facilitating the discharge of wood chips, resulting in smoother and faster drilling. Bursting Prevention: The force is effectively protected in a plane, minimizing the risk of bursting at the beginning of drilling, ensuring a safer woodworking experience. Stable Clamping: The universal shank type and round designed drill tail ensure stable clamping, allowing for precise and reliable drilling performance. Versatile Application: Suitable for square hole drills and square tenon machines, making it a versatile tool for various woodworking tasks. Specification: Condition: 100% Brand New Item Type: Square Hole Drill Bits Material: Bearing Steel Color: As picture shown Uses: Suitable for wood products such as density board, medium fiber board, particle board, wood, etc., suitable for square hole drills and square tenon machines Specification: 1/4, 5/16, 3/8, 1/2 Specification Hole Size Shank Diameter Grooves Depth Total Length 1/4 6.4mm / 0.3in 4.1mm / 0.2in 45mm/ 1.8in 170mm / 6.7in 5/16 8mm / 0.3in 5.5mm / 0.2in 60mm / 2.4in 200mm / 7.9in 3/8 9.5mm / 0.4in 6.5mm / 0.3in 60mm / 2.4in 210mm / 8.3in 1/2 12.7mm / 0.5in 8.5mm / 0.3in 60mm / 2.4in 210mm / 8.3in Package List: Condition: 100% Brand New Item Type: Square Hole Drill Bits Material: Bearing Steel Color: As picture shown Uses: Suitable for wood products such as density board, medium fiber board, particle board, wood, etc., suitable for square hole drills and square tenon machines Specification: 1/4, 5/16, 3/8, 1/2 Specification Hole Size Shank Diameter Grooves Depth Total Length 1/4 6.4mm / 0.3in 4.1mm / 0.2in 45mm/ 1.8in 170mm / 6.7in 5/16 8mm / 0.3in 5.5mm / 0.2in 60mm / 2.4in 200mm / 7.9in 3/8 9.5mm / 0.4in 6.5mm / 0.3in 60mm / 2.4in 210mm / 8.3in 1/2 12.7mm / 0.5in 8.5mm / 0.3in 60mm / 2.4in 210mm / 8.3in Note: Cannot be used on metal, concrete, glass and gypsum board. Package List 4 x Square Hole Drill Bits