Handdo 7Pcs Square Hole Drill Bit, High Speed Steel Sharp Durable Mortising Chisel Set 6/25, 1/4, 5/16, 3/8, 2/5, 1/2, 9/16 Inch

7Pcs Square Hole Drill Bit
Material: HSS
Hardness: HRC 48~50
Slotting flute diameter: 6/25 inches (6 mm), 1/4 inches (6.4 mm), 5/16 inches (8 mm), 3/8 inches (9.5 mm), 2/5 inches (10 mm), 1/2 inches (12.7 mm), 9/16 inches (14 mm)

Using steps:
1. Drag the core and shell into the equipment fixture and drag.
2. Take a 0.5 - 1 mm thick sheet (metal sheet or hard plastic sheet) stuck at the step of the drill shell.
3. After fixing the drill core, take down the slice, and then adjust the angle of the drill shell and press it upward and clamp it (the purpose is to form a 0.5 - 1 mm gap between the head of the drill core and the inner angle of the drill shell to avoid the bit stuck dead).

Notice:
Square hole drill needs to cooperate with square hole drill machine (mortise and tenon) use and can not use with hand-operated electric drill

Package Included:
1 X 6/25 Inch (6.0mm) Drill Bit
1 X 1/4 Inch (6.4mm) Drill Bit
1 X 5/16 Inch (8.0mm) Drill Bit
1 X 3/8 Inch (9.5mm) Drill Bit
1 X 2/5 Inch (10mm) Drill Bit
1 X 1/2 Inch (12.7mm) Drill Bit
1 X 9/16 Inch (14mm) Drill Bit