The reamer diameter accounts for the 0.001" oversized diameter rating, so these reamers create a looser fit than standard reamer sizes. The shank diameter is slightly smaller than the reamer diameter.

Straight-flute reamers are for general purpose cutting.

Spiral-flute reamers create a smoother finish than straight flutes and work well in keyways and other applications with an interrupted cut. Reamers with a right-hand spiral pull chips upward as they cut, so they’re often used in blind holes. Reamers with a left-hand spiral push chips downward as they cut, making them good for through holes.

Ream a looser fit than standard reamer diameters. These reamers are solid carbide for exceptional wear resistance and high accuracy in addition to excellent abrasion and heat resistance when cutting hard and abrasive materials. They require rigid tool holding to prevent breakage and are not for use with hand-held tools. The reamer diameter accounts for the 0.001” oversized diameter rating.