Unlike standard reamers, which are unusable once they become worn, these can be returned to their original size for finishing holes. After the reamer is worn down, tighten the set screw to expand the diameter, grind the reamer to its original size, and get back to work.

These are not designed for producing holes larger than the listed diameter or for producing holes of various sizes. The set screw should not be loosened.

Turn these reamers by hand with an adjustable wrench or straight-handle tap wrench (sold separately).

Straight Flute—The most common flute style, these reamers are suitable for a wide range of applications, but not recommended for holes with a keyway or other breaks in the surface.

Spiral Flute—Since these reamers clear chips better than straight flutes, they leave holes with a smoother finish. They're better for holes with breaks in the surface, such as a keyway, because they cut continuously across the breaks instead of moving in and out.

High-Speed Steel—Durable and wear resistant, these are good for general purpose reaming in most materials.

Left-Hand Spiral—These reamers push chips downward as they cut, so they're often used in through holes.