Flutes have a low helix angle to provide the cutting forces required for difficult-to-machine material, such as hardened steel and iron. Made of solid carbide, these end mills are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. Their extreme hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent the end mill from breaking. They have a ball end for milling rounded slots, slopes, and contours. All are center cutting, allowing plunge cuts into a surface.

Fasten one insert to the center of these end mills and three more to the sides, and you can use them for drilling, shoulder milling, contouring, and finishing. When the cutting edges dull, switch out the inserts instead of replacing the whole tool. These end mills help you reduce waste and costs in high-volume jobs. The inserts are locked in place with a screw for a hold that’s strong enough to handle the high speeds of a CNC machine.

Inserts have a positive rake angle, which means the cutting edge is angled to reduce vibration and prevent thin workpieces from bending. For a longer life, each insert has two cutting edges—rotate the insert when the first side wears down. They have chip breakers to stop long chips from forming, so they won’t block the flow of coolant or damage your tool. Inserts sold individually come in a clear plastic case to prevent damage during shipping. Inserts sold in packs come factory sealed from the manufacturer, which makes them easy to trace.