The standard ER collet is the most widely used clamping system in the world. Made from Alloy spring steel and fully hardened these ER collets are ideal for many machining applications including boring, milling, reaming, tapping and grinding. Unless specified differently all of our ER collets feature runout of 0.010 micron or less. ,ER collet sizes start at ER8 through ER40.
ER40 series collets have a capacity of 3mm-26mm. Each ER40 collet has a range of (1 mm). The size indicated on the collet is the largest size it can hold and can be collapsed smaller within its collapse range of (0.9mm). For example, ER40-6mm can grab a round shank from 6mm diameter to 5.1mm diameter.