Tooling & Workholding

Toolholders

The Toolholder is the essential connection between the machining center and the cutting tool. The toolholder fits into and is secured by the machining center’s spindle, and in turn secures the cutting tool such as a drill or end mill by clamping onto its shank. The taper of the toolholder matches the toolholder interface of the particular spindle. Toolholder tapers are often conical, including CAT and BT taper specifications. A different kind of taper, HSK, is not tapered at all, but instead includes a variety of flanges for securely locking the toolholder in place. Toolholders use different mechanisms for clamping the tool. A set screw can clamp onto a corresponding flat in the tool’s shank. Or, a collet can be compressed around the tool by tightening a nut that also surrounds the tool. More unusual clamping mechanisms include hydraulic toolholders, which compress a bladder of hydraulic fluid, as well as shrink fit toolholders, which clamp and release the tool by heating and cooling the toolholder’s metal to take advantage of thermal expansion and contraction. Other toolholder types use still other methods of clamping. Various clamping mechanisms aim to provide not just secure holding of the tool, but also tool concentricity to the centerline of the spindle that is accurate to a level of runout error appropriate to the tool and the machining process.

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Featured Zone Content

Gripper for machine tool

Video: Parts Gripper Allows Machine To Act As Its Own Robot


This footage shows a workpiece gripper that enables a machine to load and unload workpieces on its own.

toolholder balancing machine

Video: Balancing Tools And Toolholders


This video provides both the argument and methodology for performing offline balancing of tool/toolholder assemblies for high speed machining centers.



Techniks SFS12

Modular Shrink-Fit Adapters Designed for Improved Holding Power

By: Jedd Cole
Techniks SFS12 modular shrink-fit adapters feature an internal drawbar design for improved holding power and faster tool changes.

Carmex Brochure Features Swiss-Type Tools

By: Lori Beckman
The Tiny Tools line has been expanded with the CBR incorporating an advanced chipbreaker for improved chip evacuation in boring and profiling operations.

Schunk Tendo Aviation

Hydraulic Toolholder Maintains Runout Accuracy

By: Jedd Cole
Schunk is expanding its line of hydraulic expansion toolholders with the Tendo Aviation designed for demanding applications such as those commonly performed in the aerospace industry.

ITI Tooling ATC

Electrospindles Hold as Many as Eight Tools

By: Jedd Cole
ITI Tooling’s ATC series of electrospindles with built-in multi-station tool carrier have been developed specifically for boost performance on production machines and robots handling multiple operations or requiring redundant tooling.

Emuge Softsynchro

Expanded Tap Holder Line Reduces Axial Forces

By: Jedd Cole
Emuge Corp. has expanded its Softsynchro tap holder line, adding two new holder series.


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