Editing Reamer (section)

==Construction==
A typical reamer consists of a set of [[Parallel (geometry)|parallel]] straight or helical cutting edges along the length of a [[Cylinder (geometry)|cylindrical]] body. Each cutting edge is ground at a slight angle and with a slight undercut below the cutting edge. Reamers must combine both hardness in the cutting edges, for long life, and toughness, so that the tool does not fail under the normal forces of use. They should only be used to remove small amounts of material. This ensures a long life for the reamer and a superior finish to the hole.

The spiral may be [[Clockwise and counterclockwise|clockwise or counter-clockwise]] depending on usage. For example, a tapered hand reamer with a clockwise spiral will tend to self feed as it is used, possibly leading to a wedging action and consequent breakage. A counter-clockwise spiral is therefore preferred even though the reamer is still turned in the clockwise direction.

For production machine tools, the shank type is usually one of the following: a standard taper (such as [[Morse taper|Morse]] or [[Brown & Sharpe taper|Brown&nbsp;&&nbsp;Sharpe]]), a straight round shank to be held by a [[collet]], or a straight round shank with a flat for a [[set screw]], to be held by a solid toolholder. For hand tools, the shank end is usually a square drive, intended for use with the same type of [[tap wrench|wrench]] used to turn a [[Taps and dies|tap]] for the cutting of [[screw thread]]s.