High-Precision ER Collets for CNC Tool Holding
EverSource supplies ER11, ER16, ER20, ER25 and ER32 precision collets for CNC milling, drilling, routing and engraving applications. Metric and imperial bore sizes are available, with standard runout of ≤0.008 mm and selected high-precision options of ≤0.005 mm.
Manufactured from heat-treated 65Mn spring steel, our ER collets support stable clamping, repeatable tool positioning and OEM laser marking requirements.
Complete ER11–ER32 Size Range
With competitive pricing and consistent quality, our collets are suitable for both small-batch sourcing and larger production requirements.
Ultra-High Precision Concentricity
Selected high-precision grades are available with measured runout down to 0.005 mm, helping improve tool positioning, reduce vibration and support consistent machining results.
High-Quality Material with Custom Options
Made from premium 65Mn spring steel with a hardness of HRC44–48, our collets deliver excellent durability and long service life. Custom logo laser engraving is also available to support branding and OEM requirements.
ER11–ER32 Precision Collets
ER11, ER16, ER20, ER25 and ER32 collets in metric and imperial sizes, with measured runout options down to 0.005 mm.
ER Collet Applications
CNC Milling and High-Precision Machining
ER Collets are widely used in CNC milling centers and precision machining tasks. Their stable clamping force and high concentricity ensure accurate tool positioning, reduced vibration, and improved surface quality during metal cutting and contouring.
CNC Routers and Woodworking Equipment
In woodworking, engraving, and CNC router applications, ER Collets provide reliable tool holding for router bits, carving tools, and trimming cutters. They support both metric and imperial tool sizes, making them ideal for furniture manufacturing, sign-making, and general woodworking.
Drilling, Boring, and Tapping Machines
ER Collets deliver secure and steady clamping for drills, taps, reamers, and other rotating tools. Their precision and durability make them suitable for high-speed drilling, deep-hole machining, and industrial tapping operations across metalworking and automated production lines.
For a better understanding of ER collet systems, see our guide to what an ER collet is and how it works, including common sizes and CNC applications.
Why Choose Our ER Collets?
Runout ≤ 0.008 mm
Stable concentricity to reduce vibration and improve machining accuracy and surface finish.
Full Size Range ER11 – ER32
Full range of standard sizes in both metric and imperial to fit various cutting tools.
Metric & Imperial Sizes Available
Available in a wide range of metric and imperial bore sizes to meet different CNC machining and tool-holding requirements.
ER Collet Size Chart & Dimensions
This ER collet size chart covers ER11, ER16, ER20, ER25 and ER32 series, including available bore sizes, clamping ranges and key dimensions.
Use the table below to compare ER collet sizes and select the appropriate series for your CNC tooling requirements.
| Model | Available Bore Sizes (mm) | D1 (mm) | D2 (mm) | L (mm) |
|---|---|---|---|---|
| ER11 | 1 / 1.5 / 2 / 2.5 / 3 / 3.175 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 7.5 / 8 | 1–8 | 11.5 | 18.5 |
| ER16 | 1 / 1.5 / 2 / 2.5 / 3 / 3.175 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 7.5 / 8 / 8.5 / 9 / 9.5 / 10 / 10.5 / 11 / 11.5 / 12 | 1–12 | 17 | 27.5 |
| ER20 | 1 / 1.5 / 2 / 2.5 / 3 / 3.175 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 7.5 / 8 / 8.5 / 9 / 9.5 / 10 / 10.5 / 11 / 11.5 / 12 / 12.5 / 13 / 13.5 / 14 / 14.5 / 15 | 1–15 | 21 | 31.5 |
| ER25 | 1 / 1.5 / 2 / 2.5 / 3 / 3.175 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 7.5 / 8 / 8.5 / 9 / 9.5 / 10 / 10.5 / 11 / 11.5 / 12 / 12.5 / 13 / 13.5 / 14 / 14.5 / 15 / 15.5 / 16 / 16.5 / 17 / 17.5 / 18 / 18.5 / 19 / 19.5 / 20 | 1–20 | 26 | 34 |
| ER32 | 1 / 1.5 / 2 / 2.5 / 3 / 3.175 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 7.5 / 8 / 8.5 / 9 / 9.5 / 10 / 10.5 / 11 / 11.5 / 12 / 12.5 / 13 / 13.5 / 14 / 14.5 / 15 / 15.5 / 16 / 16.5 / 17 / 17.5 / 18 / 18.5 / 19 / 19.5 / 20 / 20.5 / 21 / 21.5 / 22 | 1–22 | 33 | 40 |
How to Choose the Right ER Collet Size
ER11 Collet
For compact CNC spindles and smaller cutting tools.
ER16 Collet
For engraving, routing and light-duty milling applications.
ER20 Collet
A versatile choice for general CNC milling and routing.
ER25 Collet
For larger cutting tools and wider clamping requirements.
ER32 Collet
For applications requiring a broader tool diameter range.
For a more detailed comparison of ER11, ER16, ER20, ER25 and ER32, read our ER collet size comparison guide to understand the differences in clamping range, tool size and typical CNC applications.
ER Collet Types and Precision Options
ER collets are available in different series and precision grades to suit different CNC machining requirements. EverSource currently supplies ER11, ER16, ER20, ER25 and ER32 collets, covering both metric and imperial bore sizes.
Standard precision ER collets are available with runout of ≤0.008 mm, while selected high-precision models can achieve runout down to ≤0.005 mm for applications requiring better concentricity and machining accuracy.
Standard ER Collets
Runout ≤0.008 mmSuitable for general CNC milling, routing and machining applications.
High-Precision ER Collets
Runout down to ≤0.005 mmDesigned for applications requiring lower runout and improved tool concentricity.
Metric Sizes
Multiple bore sizes availableAvailable across ER11, ER16, ER20, ER25 and ER32 series for common metric tool shanks.
Imperial Sizes
Inch-size options availableSuitable for markets and machines using imperial tooling specifications.
OEM Laser Marking
Custom branding availableLaser marking and OEM branding options are available for distributors and volume buyers.
Even a high-quality collet may produce excessive tool runout when contamination, incorrect assembly or improper tightening affects the complete toolholding system. Learn more about ER collet runout causes, measurement and solutions.
About Ever Source
Shanghai Ever Source International Trade Co., Ltd. was established in 2003 and has more than 20 years of experience supplying industrial products to customers in Europe and North America.
By working with a network of qualified Chinese manufacturers, we help customers compare product specifications, quality levels, lead times and costs. Our engineering and inspection support allows us to recommend suitable products for different machining and procurement requirements.
Our goal is to simplify sourcing, reduce communication time and provide reliable products with consistent quality and competitive value.
Our Production Workshop & Warehouse
Quality Inspection & Supplier Verification
We review supplier capabilities and conduct product inspections based on the agreed specifications before shipment.
What sizes are available for ER collets?
EverSource supplies ER11, ER16, ER20, ER25 and ER32 collets, covering bore sizes from 1 mm up to 22 mm depending on the series.
What is the maximum size of an ER20 collet?
Our ER20 series is available in bore sizes from 1 mm to 15 mm.
What is the difference between ER11, ER16, ER20, ER25 and ER32?
The main differences are overall dimensions, compatible chuck size and available clamping range. Larger ER series generally support larger tool shank diameters.
Are metric and imperial ER collet sizes available?
Yes. Metric and imperial sizes are available depending on the series and order requirements.
When can I expect a response?
Our business hours are Monday to Friday, 9:00 AM to 6:00 PM (UTC+8). Messages received outside business hours will be answered as soon as possible on the next working day.
How do you ensure product quality?
We inspect product dimensions and runout before shipment. For selected orders, inspection records, photos or test videos can be provided upon request.
What shipping methods are available?
We can arrange shipment by express courier, air freight or sea freight according to the order quantity, destination and delivery requirements. FedEx and other international courier options are available.
How do I request a quotation?
Please send us the required ER series, bore sizes, precision grade, quantity and any OEM packaging or engraving requirements. We will review your specifications and provide a quotation.
Frequently Asked Questions
Thank you for your interest in our products! If you have more questions, please contact us. We look forward to assisting you!
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