ER20 series coolant collets have a capacity of .142-.512 inches. Each ER20 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, ER20-1/4 can grab a round shank from .250 diameter to .235 diameter. Please refer to our ER20 Collet print for general ER20 dimensions.
