Main Features:

👷‍♂Top Quality：Made from high speed steel,after professional heat treatment,HRC48~50,ensuring its high hardness and high concentricity.

👷‍♂Size：Packaged with 4 different size for your choose, 1/4"(6.4mm), 5/16"(8mm), 3/8"(9.5mm), 1/2"(12.7mm). These long square drill bits set can meet most of your needs, and each drills packed in a single plastic case, easy to maintain.

👷‍♂Efficient and labor-saving: Our woodworking squre drill bit all designed with long drill core and square chisel,easy to lock the hole on the wood, then you can get different mortisers quickly.

👷‍♂Widely Application: Great for drilling square holes in wood with a mortising machine or a mortising attachment.Fits all mortising machines and drill press attachments. Square hole drill is mainly used for woodworking aspects.

Specifications:

• Material: High-Speed Steel.
• Hardness: 56HRC.
• Clamping shank diameter:
  1/4 INCH (6.4MM)
  3/8 INCH (9.5MM)
  9/16 INCH (14MM)
  5/8 INCH (16MM)  
• Middle terrible diameter: Total length: 19.5 cm / 7.68 in; Diameter: 6.8 mm / 0.27 in
• Square hole drill cannot be used on an electric drill, drill square holes need to fit a square hole drill drilling (mortise and tenon machine) to use. Mortise and tenon square hole drilled by the terrible + outer sleeve in the middle of the combination.

Package Include:

• TYPE1: 1/4 INCH (6.4MM) + 3/8 INCH (9.5MM).
• TYPE2: 1/4 INCH (6.4MM) + 3/8 INCH (9.5MM) + 9/16 INCH (14MM).
• TYPE3: 1/4 INCH (6.4MM) + 3/8 INCH (9.5MM) + 9/16 INCH (14MM) + 5/8 INCH (16MM) .