Counter boring or finish boring is a deep hole drilling process that requires a workpiece with a pre-existing bore. Counter boring is used to enlarge the existing bore or to remove excess stock. Counter boring tools are often used on low power machines were a small diameter solid boring tool is used for the pre-bore and then a counter boring tool is used to finish the job.
Our indexable counter boring tools are available in both push and pull styles. Additionally our counter boring tools may be self piloting or when concentricity is of utmost importance they can be designed to pilot off of the pre-bore. See the General Information section below for more information.
Consider these unique advantages of American Heller's Unidex/BTA Indexable Counter Boring Tools.
Tools produced to an accuracy of ±.0005" on diameter resulting in closer tolerance holes and accurate indexing of inserts and pads.
Self-piloting design for producing straight holes, even for bore depths up to 100 times the tool diameter.
Runout as little as .001" per foot can be obtained.
Stock removal up to .650" per side depending on tool size.
Tools produced to bore one size or to cover a complete range of sizes.
Tools available in either push or pull boring versions, in either I.D. or O.D. chip removal. BTA single cutter pull type boring tools for your critical straightness requirements.
Carbide inserts with factory ground circle lands (available coated or uncoated) insure better hole finish and closer I.D. tolerances. Hole tolerances of ±.001" I.D. obtainable.
Preground carbide guide pads are reversible for double the life.
Fiber or nylon pads reduce vibrations for better bore finishes and longer insert life.
Only 4 different insert required to cover te complete range from 1.181" and up.
Note: Hole tolerances, concentricity, surface finish and runout will be affected by a number of factors including machine condition, alignment, boring bar straightness, bushing size, etc.
Counterboring - Counter Boring or Finish Boring tools are used with a pre-existing bore. They are used to enlarge an existing bore or to remove any excess stock. Counter Boring tools are often used on low power machines were a small diameter Solid Boring tool is used for the pre-bore and then a Counter Boring tool is used to finish the job. Counter Boring is also used when there is a heat treat process required after the initial hole is drilled or if a stepped hole is required.