Features Time Saving: Reduce labor strength, speed up construction, and lower costs in building, installation, renovation, and decoration industries. Multiple Specifications: Use different square hole drill bit sizes with the appropriate power for varied square hole requirements. High Speed Steel: Made of heat-treated high-speed steel for a long-lasting, incisive square chisel with high hardness. Easy to Use: Compatible with mortising machines, doubling the drilling effect and eliminating the need for additional tools. Primary Use: Ideal for drilling square holes in wood using a mortising machine or attachment. Specification: Item Type: Woodworking Square Drill Bits Set Material: HSS Punch Size: 6.4mm (1/4in) 8.0mm (5/16in) 9.5mm (3/8in) 12.7mm (1/2in) Package List: Item Type: Woodworking Square Drill Bits Set Material: HSS Punch Size: 6.4mm (1/4in) 8.0mm (5/16in) 9.5mm (3/8in) 12.7mm (1/2in) Package List 4 x Woodworking Square Drill Bit 4 x Storage Box