ER16 Collets- ER16 Standard Collets Our ER16 collets have a capacity ranging from . 0625 - . 4062 inches or in metric sizes from 1mm up to 10mm. The number shown on the collet is the largest size that particular collet can hold, but it can be tightened to a smaller size.

The standard series are: ER-8, ER-11, ER-16, ER-20, ER-25, ER-32, ER-40, and ER-50. The "ER" name came from an existing "E" collet (which were a letter series of names) which Rego-Fix modified and appended "R" for "Rego-Fix". The series number is the opening diameter of the tapered receptacle, in millimetres.

After doing some research, it seems that sk collets are better in just about every way. The taper is half the angle of er which results in lower runout, better grip, higher rigidity. Only downside i see is that the clamping range of each collet is a half mm instead of a full mm like er.

Collets have a life span of 400-600 hours, which roughly translates to between two and three months with the collet being used eight hours a day. When inspecting your collet, metallic damage, such as bell mouthing or burrs, should be checked with every tool change.