General description This 6-piece Wood Drill Bits Square Hole Hollow Chisel Steel Tools Set is designed for woodworking, specifically for drilling square holes. Made from high-speed steel, these drill bits are sturdy, practical, and efficient, featuring heat-treated cutting edges for high hardness and fast cutting. The innovative design of the drill guide minimizes tearing at the start of use, ensuring that the drill bit operates smoothly without offset or blockage. Technical specifications Material: High-speed steel Quantity: 6 pieces Sizes: 6.4mm, 8mm, 9.5mm, 12.7mm, 14mm, 16mm Compatibility and accessories Ideal for use with a mortising machine or mortising attachment Not suitable for electric drills or bench drills Usage Designed for drilling square holes in wood, including MDF, plastic, particle board, channel wood, pine wood, and basswood Not suitable for processing metal, glass, concrete, or gypsum board Other information Each drill bit is packed in a single plastic case for