Square Tenon Drill Mortise And Tenon Drilling Woodworking Square Hole Drill Feature: Materials: these square hole drills are made of high speed steel, heat treated, with high hardness bits and compatible with sharp square chisels, with long service life High efficiency: the woodworking bit is equipped with a long core and square chisel, which is easy to lock the hole on the wood, so as to obtain different mortar quickly. And it's labor saving. Size: 4 different sizes are available for you to choose. Square hole, 1 / 4 inch (6.4 mm), 5 / 16 inch (8 mm), 3 / 8 inch (9.5 mm), 1 / 2 inch (12.7 mm). See the picture for more details, it's more intuitive. The drill bit is easy to maintain and can be protected by most of these plastic boxes. Scope of application: suitable for drilling square holes in wood with mortise machine or mortise accessories. It is also suitable for bench drilling machine. It is recommended to use wood with density board, pressing board and plastic wood. Note: these square drills are not suitable for any hand drill. Make sure that the wood floor is at a 90 degree angle to the drill bit. Note: it is not recommended to use in bearing wall, stainless steel plate and tempered glass. Please pay attention to safety when using. Package Content: 1 x drilling tool tempered glass. Please pay attention to safety when using. machine or mortise accessories. It is also suitable for bench drilling machine. It is recommended to use wood with density board, pressing board and plastic wood. Note: these square drills are not suitable for any hand drill. Make sure that the wood floor is at a 90 degree angle to 1 x drilling tool these square hole drills are made of high speed steel, heat treated, with high hardness bits and compatible with sharp square chisels, with long service life it is not recommended to use in bearing wall, stainless steel plate and