Reamers are used to remove material from, deburr, or enlarge the inside of previously formed holes. They have cutting flutes on one end and a straight shank on the other. Reamers can either be used with hand or machine tools, such as turret lathes and drill presses.

Reamers used with machines are called chucking reamers. They cut on the 45-degree bevel lead; the bevel lead is the angle at the top of the flute. Hand reamers cut both on the bevel lead and the taper lead, which is the full length of the flute. There are also taper pin reamers, which are designed to ream holes for standard taper pins. Taper pin reamers are used with both hand and machine tools.

The number of flutes on the reamer determines how fast it can be fed into the hole, how rigid it is, and the space for chips. The more flutes, the more space, feed speed, and rigidity. The type of flute also comes into play. Straight flutes are commonly used, but spiral and helical flutes prevent chip buildup and can be used at higher speeds.