ER40 series coolant collets have a capacity of .423-1.00 inches. Each ER40 coolant collet has a range of .015 inches. The size indicated on the collet is the largest size it can hold and can be collapsed smaller within its collapse range mentioned above. For example, ER40-7/16 can grab a round shank from .4375 diameter to .4225 diameter. Please refer to our ER40 Collet print for general ER40 dimensions.
