End mill

They can have several end configurations: round (ball), tapered, or straight are a few popular types.

Several broad categories of end- and face-milling tools exist, such as center-cutting versus non-center-cutting (whether the mill can take plunging cuts); and categorization by number of flutes; by helix angle; by material; and by coating material.

For finishing end mills, it is common to see more tight spiral, with helix angles 45° or 60°.

There exist end mills with variable flute helix or pseudo-random helix angle, and discontinuous flute geometries, to help break material into smaller pieces while cutting (improving chip evacuation and reducing risk of jamming) and reduce tool engagement on big cuts.

Some modern designs also include small features like the corner chamfer and chipbreaker.

It is becoming increasingly common for traditional solid end mills to be replaced by more cost-effective inserted cutting tools (which, though more expensive initially, reduce tool-change times and allow for the easy replacement of worn or broken cutting edges rather than the entire tool).

For the time being however, this only generally applies to larger diameter end mills, at or above 3/4 of an inch.

These end mills are generally used for roughing operation, whereas traditional end mills are still used for finishing and work where a smaller diameter, or a tighter tolerance, are required; modular tooling introduces additional margins of error that can compound with each new component, whereas a solid tool can provide a smaller tolerance range for the same price level.

In the USA, metric is readily available, but it is only used in some machine shops and not others; in Canada, due to the country's proximity to the US, much the same is true.

Shell end cutters are used for large flat surfaces and for angle cuts.

Depending on the material being milled, and what task should be performed, different tool types and geometry may be used.

For instance, when milling a material like aluminum, it may be advantageous to use a tool with very deep, polished flutes, a very sharp cutting edge and high rake angles.

Though PCD veins is not a coating, some end mills are manufactured with a 'vein' of polycrystalline diamond.