Drillco Cutting Tools DRILLCO #429N140 Reamer; Construction; Spiral Flute; 5/8 in. Nominal Diameter; 6 in. Overall Length; 1-1/16 in. Diameter Hex Nut Shank; Black and Gold High Speed Steel

Manufactured from a premium grade of m-7N molybdenum high speed steel. The Nitro heavy-duty construction reamers have a Ferritic Nitro carburizing surface treatment which gives a hard protective layer to the reamer. This increases hardness (Rc 75-80) without increasing brittleness which is measurably harder than high speed steel. Body and clearance are gold and black surface treated for maximum lubricity.