ER Collet Sizes
ER collets, while they are designed for tool holding, also work great for work holding in small lathes. They also have many inherent benefits of other solutions.
High Precision and Concentricity: Designed to minimize runout, ER collets provide high concentricity, ensuring that workpiece or tools are held securely and accurately.
Reliable Performance: ER collets provide consistent and repeatable accuracy. Their design ensures even distribution of clamping forces, reducing slippage and vibrations during machining.
Wide range of clamping: ER collets can accommodate a variety of workpiece or tool diameters. Fewer collets are needed to cover a broad range of tools, reducing cost and simplifying tool changes.
Self-Release Feature: When the collet nut is loosened, the collet automatically disengages from the tool, preventing sticking or damage and making for quicker and easier tool changes
| ER Collet | Length | Diameter | Clamping Range |
|---|---|---|---|
| ER-11 | 18mm (0.71") | 11.5mm (0.45") | 0.5 – 7mm (0.020—0.276") |
| ER-16 | 27.5mm (1.08") | 17mm (0.67") | 0.5 – 9mm (0.020—0.354") |
| ER-20 | 31.5mm (1.24") | 21mm (0.83") | 1 – 13mm (0.039—0.512") |
| ER-25 | 34mm (1.34") | 26mm (1.02") | 1 – 16mm (0.039—0.630") |
| ER-32 | 40mm (1.57" | 33mm (1.30") | 1 – 21mm (0.039—0.827") |
| ER-40 | 46mm (1.81") | 41mm (1.61") | 3 – 26mm (0.118—1.024") |
There are several types of collets that look like ER collets. If your collet looks like an ER collet but does not match one of the sizes shown above, it is a different type of collet and not an ER collet.
The table below shows the available sizes of ER collets. Click the collet size at the top of the column (ER-32, for example) to go to the page that lists all the collets in that size range. This makes ordering several collets in the same size range simple.
| Size | Range (in) | Range (mm) | ER-11 | ER-16 | ER-20 | ER-25 | Metric ER-25 |
ER-32 | Metric ER-32 |
ER-40 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/32" | 0.020 – 0.039" | 0.5 – 1.0mm | 4797 | 4613 | ||||||
| 1/16" | 0.039 – 0.079" | 1.0 – 2.0mm | 4601 | 4614 | 4620 | 5053 | 4558 | |||
| 3/32" | 0.079 – 0.118" | 2.0 – 3.0mm | 4398 | 4615 | 4621 | 5054 | 4332 | 4559 | 4333 | |
| 1/8" | 0.118 – 0.157" | 3.0 – 4.0mm | 4454 | 4434 | 2443 | 5055 | 4332 | 4560 | 4333 | 5885 |
| 3/16" | 0.157 – 0.197" | 4.0 – 5.0mm | 4455 | 4435 | 4622 | 5056 | 4332 | 4561 | 4333 | 5886 |
| 7/32" | 0.197 – 0.236" | 5.0 – 6.0mm | 4399 | 4616 | 4623 | 5057 | 4332 | 4562 | 4333 | 5887 |
| 1/4" | 0.236 – 0.276" | 6.0 – 7.0mm | 4456 | 4436 | 2444 | 5058 | 4563 | 5888 | ||
| 5/16" | 0.276 – 0.315" | 7.0 – 8.0mm | 4617 | 4624 | 5059 | 4332 | 4564 | 4333 | 5889 | |
| 11/32" | 0.315 – 0.354" | 8.0 – 9.0mm | 4619 | 4625 | 5060 | 4565 | 5890 | |||
| 3/8" | 0.354 – 0.394" | 9.0 – 10mm | 4618 | 2445 | 5061 | 4332 | 4566 | 4333 | 5891 | |
| 13/32" | 0.394 – 0.433" | 10 – 11mm | 4626 | 5062 | 4567 | 5892 | ||||
| 7/16" | 0.433 – 0.472" | 11 – 12mm | 4627 | 5063 | 4332 | 4568 | 4333 | 5893 | ||
| 1/2" | 0.472 – 0.512" | 12 – 13mm | 4628 | 5064 | 4569 | 5894 | ||||
| 17/32" | 0.512 – 0.551" | 13 – 14mm | 5065 | 4332 | 4570 | 4333 | 5895 | |||
| 9/16" | 0.551 – 0.591" | 14 – 15mm | 5066 | 4332 | 4571 | 4333 | 5896 | |||
| 5/8" | 0.591 – 0.630" | 15 – 16mm | 5067 | 4332 | 4572 | 4333 | 5897 | |||
| 21/32" | 0.63 – 0.669" | 16 – 17mm | 4573 | 5898 | ||||||
| 11/16" | 0.669 – 0.709" | 17 – 18mm | 4574 | 4333 | 5899 | |||||
| 23/32" | 0.709 – 0.748" | 18 – 19mm | 4575 | 5900 | ||||||
| 3/4" | 0.748 – 0.787" | 19 – 20mm | 4576 | 4333 | 5901 | |||||
| 13/16" | 0.787 – 0.827" | 20 – 21mm | 4578 | 5903 | ||||||
| 27/32" | 0.827 – 0.866" | 21 – 22mm | 5904 | |||||||
| 7/8" | 0.866 – 0.906" | 22 – 23mm | 5905 | |||||||
| 15/16" | 0.906 – 0.945" | 23 – 24mm | 5906 | |||||||
| 31/32" | 0.945 – 0.984" | 24 – 25mm | 5907 | |||||||
| 1" | 0.984 – 1.024" | 25 – 26mm | 2908 |