Drill Bushing Specifications

• Finish Ground bushings, 1/8″ to 1″ I.D., are held within .0003″ concentricity T.I.R. (Total Indicator Reading). Other sizes are held within .0005″ T.I.R.
• Unground bushings with .010/.020 grinding stock on the O.D. are concentric within .006″. The letter “U” as a suffix to the ANSI symbol indicates an unground O.D. for custom grinding.
• Lengths longer than ANSI Standard or relieved bushings will meet the above tolerances at the drill exit end only.
• Standard and Special bushings will be manufactured from thru-hardened tool steel and heat treated to 61-65 RC unless instructed otherwise by the customer.
• No-Counterbore bushings will be supplied unless requested otherwise. No-Counterbore bushings allow for truer alignment, more accurate holes, less tool wear, and less problems with chips packing up in the I.D. of the bushing. Acme will, however, supply counterbored bushings when requested.
• Specifications for Metric Bushings are in the Standard Metric Bushing Section.