Adjustment-Free, Offset, Rotary Broach Toolholder

March 14, 2017
Adjustment-Free, Offset, Rotary Broach Toolholder

Somma Tool Co. announces the development of a broach toolholder that is reportedly uniquely interchangeable among any style of ER collet chuck. The compact, adjustment-free, offset, rotary broach toolholder will thread to an existing ER (16, 20, 25 and 32) collet chuck and features a built-in 1-degree wobble cutting edge for offset rotary broaching.

The broaching holder allows the user to swap one holder among different styles shanks, such as round, Capto, VDI, Morse, CAT and NMTB taper. This one holder reduces the need for toolholder adapter bushings, making it economical and versatile, according to the company.

The patent-pending rotary broach holders use SommaSwiss broaches with 8mm-dia. shanks and 1/2"-dia. shank broaches from Somma and other broach manufacturers. They are adjustment-free for on-center applications that do not require offset compensations.

Related Glossary Terms

  • broach


    Tapered tool, with a series of teeth of increasing length, that is pushed or pulled into a workpiece, successively removing small amounts of metal to enlarge a hole, slot or other opening to final size.

  • broaching


    Operation in which a cutter progressively enlarges a slot or hole or shapes a workpiece exterior. Low teeth start the cut, intermediate teeth remove the majority of the material and high teeth finish the task. Broaching can be a one-step operation, as opposed to milling and slotting, which require repeated passes. Typically, however, broaching also involves multiple passes.

  • chuck


    Workholding device that affixes to a mill, lathe or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated. May also be fitted to the machine table to hold a workpiece. Two or more adjustable jaws actually hold the tool or part. May be actuated manually, pneumatically, hydraulically or electrically. See collet.

  • collet


    Flexible-sided device that secures a tool or workpiece. Similar in function to a chuck, but can accommodate only a narrow size range. Typically provides greater gripping force and precision than a chuck. See chuck.

  • shank


    Main body of a tool; the portion of a drill or similar end-held tool that fits into a collet, chuck or similar mounting device.

  • toolholder


    Secures a cutting tool during a machining operation. Basic types include block, cartridge, chuck, collet, fixed, modular, quick-change and rotating.