CNC tooling
ER Collets and Collet Chucks for CNC Milling and Routers
Find ER collets for collet chucks on VMCs, milling machines and CNC routers, along with new and used BT tool holders. Tell us the ER size, the shank diameter you need to clamp and the quantity for price and availability.
- ER collets for chucks
- New and used BT holders
- Care and fitting guidance
- Pan-India shipping
Toolholder and Collet Maintenance
To ensure proper performance of your toolholders, overall cleanliness of toolholder, collet pocket, collet, and nut must be maintained. It’s important to remember that all these components are manufactured to perform within tolerances of ten-thousandths (.0001”) of an inch.
Any dirt, dust, oil, chips, or other contaminant left on the spindle, taper, flange, collet, collet pocket, or nut can cause poor T.I.R. (runout) leading to premature wear of cutting tool, toolholder, and spindle mouth.
We recommend a regular preventive maintenance program be implemented in your shop to protect your investment in cutting tools, toolholders, and collets, and reduce scrap.
BT Taper Sizes
BT tapers come in different sizes, table of which you can find below :
BT Toolholders, ATC and Safe Storage
BT tools allow use of ATC (Automatic Tool Change) technology to maximize the speed and productivity of manufacturing.
BT tool holders perform work with high strains and pressures, so be sure to store them safely without any chance for the tool being damaged – as this may cause imbalance that can be critical at high speeds and precise CNC machinery.
BT Tool Holders and ER Collet Chucks
Depending on your machining needs, choosing the right BT holder makes the job more efficient. Our team can help you select a suitable BT tool holder or ER collet chuck for your application.
We supply new and used BT tool holders. Tell us the brand, taper size and holder type you need.
Your next step
Get price & availability
Share the model or part number and quantity. Attach a nameplate photo or BOM on the quote form if you have one.
Buyer guide
ER Collet Sizes and Clamping Ranges
ER collets follow a common standard series, so a collet of a given size fits any ER chuck or nut of the same size. Each collet clamps over a small range, typically about 1 mm (about 0.5 mm on the smallest sizes), so you need the collet that matches your shank diameter.
| ER size | Typical maximum clamping diameter | Common use |
|---|---|---|
| ER11 | 7 mm | Small router and engraving spindles |
| ER16 | 10 mm | Small tools, compact chucks |
| ER20 | 13 mm | Router spindles, small milling tools |
| ER25 | 16 mm | General milling and drilling |
| ER32 | 20 mm | General milling on VMCs |
| ER40 | 26 mm | Larger drills and end mills |
Confirm the exact range against the collet's marking, which shows its nominal and minimum diameter.
How to Fit an ER Collet Correctly
- Clean the collet, the nut and the chuck's taper. Dirt here is the main cause of runout.
- Snap the collet into the nut first, tilting it until the eccentric ring engages. Do not drop the collet into the chuck and then screw the nut on.
- Screw the nut on loosely, insert the tool to at least the minimum grip length, then tighten.
- Tighten with the correct spanner to the chuck maker's torque. Under-tightening lets the tool slip; over-tightening damages the collet.
- Never tighten a nut on an empty collet, as this can deform it.
Replace collets that show wear marks, cracks or loss of spring, and use sealed collets where through-tool coolant is needed. Collets are wear parts and should be replaced periodically.
Faster quotations
What to Include in Your Enquiry
Send what you have. If a detail is unknown, say so and we will help identify it from a photo or the machine documentation.
- ER size (for example ER20 or ER32)
- Shank diameter to be clamped
- Standard or sealed (coolant) collet
- Whether you need nuts, chucks or BT holders
- Quantity required
Buyer questions
Frequently Asked Questions
How do I know which ER collet size I need?
Check the size marked on your chuck, nut or spindle nose, for example ER20 or ER32. Then choose a collet whose clamping range covers your tool shank diameter. The collet itself is marked with its nominal and minimum diameter.
Can one ER collet hold several shank sizes?
Only within a small range. A standard ER collet clamps over about 1 mm, or about 0.5 mm on the smallest sizes. For example, a 10 mm collet might hold shanks from about 9 to 10 mm. For the most accurate grip, use a collet whose nominal size matches the shank.
Are ER collets from different brands interchangeable?
Collets built to the ER standard fit any ER chuck and nut of the same size. Accuracy and spring quality vary by make, so for precision work choose collets with a stated runout grade and replace them as a set when they wear.
Why does my tool have runout in an ER collet chuck?
The usual causes are dirt on the collet, nut or taper, a worn or damaged collet, a collet fitted into the chuck before the nut, uneven tightening, or too little grip length. Clean all parts, fit the collet into the nut first and tighten to the correct torque.
Do you supply BT tool holders for ER collets?
Yes, we supply new and used BT tool holders. Tell us the taper size, such as BT30, BT40 or BT50, the holder type you need, for example an ER collet chuck, and any brand preference, and we will confirm price and availability.
How often should ER collets be replaced?
Collets are wear parts. Replace them when you see wear marks, cracks, burrs or corrosion, when they no longer grip firmly, or when runout increases. Collets used daily in production wear sooner than those used occasionally. Keeping them clean extends their life.
How do I order ER collets?
Send the ER size, the shank diameters you need and the quantity through our quote form, by phone or by email. Include any nuts, chucks or BT holders you need and we will quote them together.
Keep exploring
Related Products and Services
From requirement to quotation
Have a part number or a machine down?
Send the model, nameplate photo or a short description. We check availability, compatible alternatives and lead time, then reply with a quotation.