Glossary

An end mill is a cutting tool used in milling machines and CNC machining centers for removing material from a workpiece to create precise shapes, profiles, holes, and surface finishes. It is one of the most versatile tools in metalworking, woodworking, and plastics machining, capable of cutting in multiple directions—axially (downward into the material) and radially (sideways across the surface).

Unlike a drill bit, which can only cut in one direction (axially), an end mill is designed with cutting edges on both its tip and sides, allowing it to perform operations such as slotting, contouring, facing, pocketing, and profiling.

Design and Construction

An end mill typically consists of:

- A shank, which is clamped into the milling machine’s collet or tool holder.

- A fluted cutting section, which features helical grooves (called flutes) that form sharp cutting edges and help remove chips during machining.

- A cutting tip, which may be flat, ball-shaped, or specially contoured depending on the type of cut desired.

End mills come in a variety of shapes, sizes, and geometries to suit specific applications:

- Flat end mills: Create sharp edges and flat-bottomed slots.

- Ball nose end mills: Used for 3D contouring, sculpted surfaces, and smooth finishes.

- Corner radius end mills: Reduce tool wear and improve part strength at internal corners.

- Roughing end mills: Have serrated edges to remove large amounts of material quickly.

Materials and Coatings

High-performance end mills are typically made from high-speed steel (HSS) or carbide, with coatings such as TiN (Titanium Nitride), TiCN, or AlTiN that reduce friction, improve heat resistance, and extend tool life.

Applications

End mills are used in a wide range of industries—aerospace, automotive, mold-making, and manufacturing—to machine materials such as steel, aluminum, brass, titanium, and plastics. They are especially critical in precision CNC milling, where intricate geometries and tight tolerances are required.