Easy Chip Removal: The drill sleeve of the square hole drill bits is U-shaped, which is designed to facilitate the removal of wood chips and improve drilling efficiency. Combination Set: The woodworking square drill bits consist of a central core drill bit and a sharp outer drill sleeve. It should be used with a square drilling machine (square tenon machine). Material: The square wood drill bits are made of carbon steel, the blade is sharp and wear-resistant, the overall heat treatment (heat treatment), high hardness and long service life. Applicable: The woodworking mortising chisel is suitable for wood, including particle board, channel wood, pine, basswood, etc. Not suitable for machining metal, glass, plastic, etc. Size: Holder Diameter: 19mm (Circular); Drilling Core Length: 195mm; Slotted Flute Diameter: 5/16 inch (8 mm), 3/8 inch (9.5 mm), 1/2 inch (12.7 mm). Description: The wood square drill bits are made of carbon steel forging, integral heat treatment, high hardness, long service life longer, sharper and more wear-resistant. It will reduce the labor intensity of construction workers, speed up construction, and reduce construction costs in the construction, installation, decoration, and decoration industries. Size: Holder Diameter: 19 mm (round) Drilling Shape Length: 195 mm Slot Flute Diameter: 5/16 inch (8 mm), 3/8 inch (9.5 mm), 1/2 inch (12.7 mm) Note: Manual measurement, please allow slight errors on the size. Colors may exist a slight difference due to different screens. Package Including 3 * Square Wood Drill Bits Delivery Quantity: 3 pieces Product color: silver Product size: length 195 mm Note: Manual measurement, please allow an error of 1-3 cm.Lonvre