How to Drill a Square Hole – Tormach’s New Rotary Broach

Broach_Blog For those that just can’t put a square peg in a round hole, there’s rotary broaching – a milling method that produces a hexagonal or other polygonal holes. First, a pilot hole is drilled into the work piece, followed by a chamfer at the top – chamfering is not necessary, but for a better quality broach, it is highly recommended. Before coming into contact with the work piece, the rotary broach spins with the spindle, due to friction. Once the tool makes contact with the work piece, the spindle continues to rotate the upper portion of the tool, creating a slight oscillation and making the hexagonal (or various polygonal shape) wobble into the pre-drilled hole. Rotary_Broaching As the tool moves through the pilot hole, the oscillation pushes each edge of the cutter so the pressure is only on one edge at a time, causing tiny bits of material to be cut with a scalloping effect. Both blind- and thru-holes can be broached, depending on the thickness of the piece and the length of the broach. Tormach now carries a rotary broach in our TTS line of tools. The TTS rotary broach holder is paired with six (3 to 10 mm) hex broaches, and will fit with any rotary broach with an 8 mm shank. 35195_Rotary_Broach_Kit_IMG_0050 35195_Rotary_Broach_Kit_IMG_0043

Chris Fox

Chris comes from a publishing background with years of experience in science, technology, and engineering publications. Previously an editor with Product Design and Development and Gizmag, he has a keen eye on the maker community and the changing landscape of the world of prototyping, product development, and small-scale manufacturing. Chris has been working with clients to create Tormach's customer success stories since 2013. Follow him on Twitter @TheChris_Fox

Chris Fox