What is a Fly Cutter on a Milling Machine – Fly Cutter Definition, Types, Uses & Fly Cutter vs Face Mill

A fly cutter is a single-point rotary cutting tool primarily used on a milling machine for machining large and flat surfaces. The fly cutter is composed of a body into which one or two tool bits are inserted. Most fly cutters are available with a holder, drawbolt, thrust washer, and a left-hand carbide cutting tool. Most fly cutters simply have a cylindrical center body that holds one tool bit. It is usually a standard left-hand turning tool that is held at an angle of 30 to 60 degrees. Fly cutters with two tool bits often with a tool bit fastened on each end. These bits will be mounted at right angles to the main axis of the bar stock. Each tooth of the cutting edge requires more power from your machine, so multi-toothed cutters on the small machines do not always work well because of a lack of rigidity and power. If you are running a light-duty mill, you can probably get the best performance from a single tooth cutter. Fly cutters are often mounted in a special angled holder, when the entire unit rotating, the tool bit takes broad and shallow facing cuts. Fly cutters are similar to face mills because they both designed for face milling and their individual cutters are replaceable. But they are different in many other aspects.