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End Mill Holder, Tormach TTS, 5/16" 

End Mill Holder, Tormach TTS, 5/16"
  • Quick change adapter for 5/16" shank end mills
  • Minimal clearance height for tool change
  • Repeatable tool positioning
  • Hardened and precision ground
Part Number: 3025
Weight: 0.65 lb

Price: $24.95

In stock
Quantity:
Quick change Tormach 5/16" suitable for general milling operations and are intended to be used with end mills that have

a Weldon shank (flat surface on shank). They can also be used with certain Silver & Deming style drill bits.

The tool holder has a set screw on one side and a balancing dimple on the other side. The balancing dimple reduces vibrations at speeds above 8000 RPM.

See Chris' Tips regarding centering of end mills when using a set screw holder.

Chris Chris' Tips
Tool switching with the Tormach Tooling System (TTS) is extremely easy: Simply loosen the drawbar, slide out the current tool holder, then slip in the next and retighten. The unique geometry of the TTS tool holder ensures that, as the drawbar is tightened, the tool holder moves into an exact Z height while increasing rigidity. Each TTS holder has a shoulder that is undercut so it contacts the spindle itself, not the end of the collet. As the drawbar is tightened the collet will simultaneously squeeze the shank and be pulled upward into the spindle taper. This simultaneous action, grasping while moving up, pulls the tool holder tightly against the spindle face. The high-pressure contact between the shoulder of the tool holder and the spindle is the equivalent of a zero tolerance fit; the vertical location (Z-height) of the tool is exact. The initial placement, created by simply sliding the tool holder up until it stops, is normally within a few thousandths of an inch. The final location, after tightening the collet, is exact, highly repeatable, and not affected by the variable tension of the drawbar or wear on the collet.

Here is the complete Tormach Tooling System Catalog and the Tormach Tooling System Manual.

Here is a picture and an animated graphic showing how the Tormach Tooling System works.


Verify that the set screw is on the flat of the shank. Never attempt to hold tooling without the screw securly held to the shank.

Due to the set screw, set screw holders will slightly push the end mill to one side when the screw is tightened. This offset from center is small, but significant for end mills smaller than 5/16 in. in diameter. Consider using an ER collet holder for small diameter tools and close tolerance finishing applications. This is not significant in 1/2 in. and 3/8 in. tooling, but begins to become important on smaller cutters.

The ER-20 and ER-16 collet holders will mount tooling on center, without the offset inherent to a set screw holder. These collet holders are recommended if you are using 1/4 in. or smaller cutters that are based on a larger shank diameter, even if the shank offers a Weldon flat for mounting. The set screw holders will work for this application, but the tool will last longer and the machined finish will be better when using an ER holder.

For a list of ER collets and their clamping ranges, visit our shopping guide for ER collet sizes.