ER collets have a wide clamping range and high accuracy.
While they are designed for tool holding, they work great for
work holding in small lathes. With a full set of ER collets you
can hold any diameter that is in the clamping range of the set.
There are several sizes of ER collets as shown in this table:
ER Collet |
Length |
Diameter |
Clamping Range |
ER-11 |
18 mm (0.71") |
11.5 mm (0.45") |
0.5—7 mm (0.020—0.276") |
ER-16 |
27.5 mm (1.08") |
17 mm (0.67") |
0.5—9 mm (0.020—0.354") |
ER-20 |
31.5 mm (1.24") |
21 mm (0.83") |
1—13 mm (0.039—0.512") |
ER-25 |
34 mm (1.34") |
26 mm (1.02") |
1—16 mm (0.039—0.630") |
ER-32 |
40 mm (1.57" |
33 mm (1.30") |
1—21 mm (0.039—0.827") |
ER-40 |
46 mm (1.81") |
41 mm (1.61") |
3—26 mm (0.188—1.024") |
There are several styles of ER collet chucks, but only two are applicable to small lathes:
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|
Flange mount collet chuck |
Collet chuck with Morse taper shank |
The flange mount collet chuck mounts on your lathe like a lathe chuck.
It bolts to the spindle flange or to an adapter if required.
The advantage of this style of collet chuck is the through-hole.
You can pass material through the headstock so you can work on
long material.
The Morse taper mount collet chuck goes right into the spindle.
Because the shank is solid, it restricts the length of the work
piece you can use. You can usually put slightly more than the
length of the collet into the collet chuck.
ER collets are self-extracting, so you don’t need to worry
about getting the collet out of the chuck.
Chris' Tips
With all ER collet chucks, the collet must be snapped into the nut before placing it into the chuck. There is an eccentric ring inside the nut that engages the groove in the collet. That is what makes them self-ejecting. Tilt the collet again to remove it from the nut.
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We carry both types of collet chucks in several styles along with
many other ER collet accessories.
Here are our ER collet products.
This shows the sizes of all the ER collets we carry.
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