What is this?? For those of you unfamiliar with mortising chisels, these will drill a square hole for you. What can it do for you?? Take your time and be sure to keep things well lubricated. The shaft space is milled perfectly with no play whatsoever. That means you will get a great hold alignment that is straight and clean. No doubt these people know how to make great tools. Main Features ? Sharp -These square hole drill bits made of Carbon Steel, lengthened core, sharp cutting edge, continuous blade, quick cuttings, high efficiency. ? Our woodworking mortising chisel bits set Only use for the opening square hole and keyhole drill -- Square hole drill can not be used on an electric drill, a bench drill, drill square holes need to fit a square hole drill drilling (mortise and tenon machine) to use. ? Reduce labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries. ?Widely Applications - This square hole drill bit is suitable for wood, including MDF, MDF, particleboard, channel wood, pinewood, basswood, etc. Note: It is not suitable for processing metal, glass, plastic, concrete, gypsum board, etc. ? How to install these square drill bits? Step 1: The drill core is very sharp. Wear working gloves to avoid direct contact between your hands and the drill bit during installation. Step 2: Put the square drill shell and drill core into the jig of the square tenoning machine, and then hold the square hole drill bit by hand. Step 3: Take 0.5~1mm thick sheet (metal sheet or plastic sheet) and jam it at the step of the drill shell. After fixing the drill core, remove the sheet, then adjust the angle of the drill shell to the top to ensure clamping, so that a 0.5~1mm gap can be formed between the drill core head and the inner bevel of the drill shell, which can prevent the bit from jamming during use. ?Purchase Notes The square hole drill bits need to be used in conjunction with the mortise machine. These drill bits not usable with a handheld drill. If you want to use these drill bits on the drill press, you need accessories to connect to a drill press. Specification Material: Carbon steel Cutting diameter: 6.4mm, 9.5mm, 14mm, 16mm Package content: Square hole drill1 Customer Reviews There is a little bit of a learning curve based on the wood that you are using. I had never used these types of bits before, but I quickly realized that in order to effectively drill mortise/tenon joints without having to spend a ton of time chiseling, I could just measure and drill small pilot holes spaced just inside the span of each bit. Huge time saver! They are sharp and ready to work. - Keith Basye undefined