These are for reaming holes for taper pins. Spiral flutes provide better chip clearance and are recommended for "blind" holes. 1/4" taper per foot. Square shank allows reamers to be held in a tap wrench.
This product may contain metals and/or chemicals that are included in the State of California's latest Prop 65 warnings. Exposure may cause cancer and/or reproductive harm. For more information go to www.P65Warnings.ca.gov