CAT and BT Taper Specifications

Tech Tip: Techniks and Parlec

We have had several inquiries regarding steep taper rotary toolholders specifications.  Below you will find all of the technical reference information related to V-Flange Tolling Tapers and dimensions.

CAT V Flange Taper Specifications

• All Parlec and Techniks Rotary toolholders meets or exceeds ASME B5.50-2009 specifications and all current specification updates except where improvements are made for high speed operation.
  
• All Parlec and Techniks CAT tooling incorporates ParSymmetry for balance and chip hole for identification.
  

About the ASME B5.50 – 2009 Standard
This Standard pertains to the standardization of a basic tool holder shank and retention knob for computer numerically-controlled machining centers with automatic tool changers. The requirements are intended to provide tool holder interchangeability between machining centers with automatic tool changers of various types.

The dimensions for cone-angle control are in accordance with the International Standard ISO-1947. This Standard will improve the understanding of the “CAT” toolholder, its associated components, and nominal operational values. It unifies the principle components of the basic machine tool holder interface—toolholders hank and spindle receiver geometry, pull stud, and conical taper information--into a single-source reference, providing instant access to information.

This new information also eliminates ambiguities and establishes absolutes for all aspects of the toolholder/spindle interface.Intended forthose involved in the design, manufacture, use, or maintenance of steep-taper (7:24) toolholders and their ancillary components.

BT Taper Specificationsƒ

• All Parlec and Techniks Rotary toolholders meets or exceeds JIS B6339-1986 specifications. ƒ
  
• Taper is toleranced so that any error increases rate of taper only. Refer to Manufacturing Specifications for tolerance specifications.

BT-40 Shank is also known as: JMTBA MAS-403 "BT", JIS B 6339 - 1986, JIS B6339 - 1992, and ISO 7388/1 - 1983.

The spindle interface JIS B 6339 as the traditional interface for milling spindles distinguishes itself through it robust design. Its field of application ranges from fine machining to heavy duty roughing. The tool holder is pulled in the milling spindle with the help of an additional pull stud.

The centering takes place via the taper contact. Therefore, the JIS B 6339 interface is primarily suitable for applications with a spindle speed of up to 12,000 rpm in an unbalanced condition.