One tool both finishes multiple diameters and enlarges holes to correct misalignment and overlap. Also known as bridge and car reamers, they have a tapered shape that fits into the narrow entry of misaligned holes and makes more contact to remove the overlapping material. Change the reamer size by moving the adjustable blades within the diameter range.

Move the blades by tightening and loosening the two nuts on the reamer. To measure size, adjust blades to a known size (such as a bushing or ring), or measure across two opposite blades with a micrometer. When the blades become worn, they can be reground or replaced.

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

Angled Blade—These reamers are better than those with straight blades for finishing holes with breaks in the surface, such as a keyway.

Tool Steel—Typically more economical but less durable than high-speed steel, these are for general purpose reaming.

Long Reach—Align holes spaced far apart with reamers that have a long, built-in pilot. A floating sleeve guides and steadies the pilot through holes.

The shank fits hex impact sockets, so you can use an impact wrench to both ream the hole and install a fastener.

Helix Flute—Prevent clogging when removing excess material with helix flutes. They also leave a smoother finish than straight flutes.

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.

Strong Hold—Magnets on the shank’s end keep these reamers from accidentally falling out of your tool.