- ER coolant collet does not have a collapse range, gripping onto undersized shank would introduce leakage - Recommended to be used with cylindrical with no flats. The full length of the shank should be inserted into the collet to prevent potential leakage - Collets are sealed up to 2,000 PSI - On size 1/8" and larger the runout is 0.0003" - No coolant discs to install, coolant is sealed by the use of special slits in the collet - Rubber coolant collets tend to deteriorate quickly, these collets do not contain rubber - Made from Alloy spring steel and fully hardened - All critical surfaces are precision ground for accurate fit