Parts List:1×Fixed Bracket 4×Square Hole Drill BitsDetailed description:Description:Our square hole drill bit adapter and drill bit set is used for drilling mortises and tenons. It is easy to install and use, reliable and practical. It can reduce workload and suitable for beginners and workers.Feature:Square Hole Drill Sleeve: The force of the drill sleeve blade is effectively protected on a flat surface, which can avoid bursting at the beginning.Alloy Drill Bit: The drill bit is forged from alloy and has high overall heat treatment hardness.U-Shaped Chip Discharge Chute: The U-shaped chip discharge chute facilitates the discharge of wood chips and improves the drilling rate.Universal Round Handle: More stable clamping, suitable for square hole machines, square tenon machines, hand electric drills, etc. Specification:Product Name: Square Hole Drill Bit AdapterMaterial: CarbideSpecifications: 6.4/8/9.5/12.7mmShank diameter: 19mmColor: Silver