Set of 4 Square Hole Drill Bits Hollow Steel Carpentry Tools Set for Square Hole Saw Wood Drill Bits Square Hole Drill Bit Hole Mortise Chisel, 1/4", 5/16", 3/8", 1/2"

Material: Made of high speed steel, high hardness up to HRC48-50, durable and practical, heat treatment, long service life. 4 different sizes: 1/4" (6.35mm), 5/16" (7.94mm), 3/8" (9.5mm), 1/2" (12.7mm). This mortise chisel set is a must have for DIY enthusiasts at home. Great for drilling square holes in wood with a mortise machine or mortising accessory. Square hole drill bit is mainly used for woodworking. Reduce the labor intensity of construction workers, speed up construction speed, reduce costs in construction, installation, renovation and decoration industries. Note: They will achieve double effect by matching use with mortise and tenon machine, square hole punching should use electric drill, hammer and other tools. (None of these are included).