1.High-quality materials: After high-density grinding and high-quality heat treatment, made of ultra-hard tungsten steel. It has high hardness, good toughness, and high concentricity performance. 2.Ideal for drilling square holes in wood with a mortising machine or mortiser. 3.It is used in conjunction with the mortising machine. If you open the square hole manually, tools such as a hand drill and a hammer are required. 4.Why choose this item: Reduces the labor intensity of construction workers while speeding up the work and reducing costs. 5.Standard chip design, easy to remove the side of the wood chips, improve drilling efficiency. Note: Due to the lighting effects and shooting angles, there is some color difference in the product, please understand. Finish Type: Silver Square Hole Size: 16mm Function: Square Hole Drill Bits Material: Stainless Steel, Metal Style: Simple Package Included: 1 Piece 16mm Square Hole Drill Bits