Made in USA. Self-Locking feature requires Tap Square and Shank match max accepted dims.  See Detailed Size chart for all dimensions.

0.220 – B Max Tap Shank Accepted

0.165 – C Max Tap Square Accepted

Easily extends the reach of thread taps.  No collet or set screws. Reusable.  For all machine and hand tapping applications.  Extension offers smallest OD in the industry.  
Metric size is conversion.  Verify the Tap mfg specs or measure Tap square and shank to assure Tap will seat with extension. 

Only the custom drift included can dislodge the Tap from the extension.

Not recommended for coolant through taps.