A reamer is a type of rotary cutting tool used in metalworking. Precision reamers are designed to enlarge the size of a previously formed hole by a small amount but with a high degree of accuracy to leave smooth sides. ... The process of enlarging the hole is called reaming.

What is the use of reamers?

A reamer is a tool that is used to widen the size of a pre-existing hole in metal by a small amount to leave smooth sides and edges – removing any burrs or rough edges. It's a pointed round file with a tip that's typically coated in diamond dust to create a hard, durable surface that's great for filing.

How accurate are reamers?

The intended use of a chucking reamer is to accurately size close-tolerance holes, which are often for dowel pins, drill bushings and other applications that require an exact fit. Standard chucking reamers can achieve hole-to-hole repeatability of 0.0005" (0.0127mm).