ER collet size help | Model Engineer & Workshop Magazine

Hi All,

Ruihan Product Page

I have been given a large collection of ER collets (sandvik 393 series) but they are a non standard size according to the Spec. the OD is 25.45mm (Nom ER25) but the length is 40.0 mm (Nom ER32). Heaven knows where id get a collet holder.

Has anyone any idea if these are of any use or should i just bin them.

Regards

Paul

Probably too good to bin.

First find someone with a 25 collet holder and check that they might fit (say this because there was 6 or 7mm clearance in the back of the ER32 holder I use.

Otherwise, just make a collet holder to suit your requirement, seen some drawings in one of the threads here for basic dimensions, obviously you will have to make radial dim to suit 25s and axial to suit 32s checking to see if there is any change to angular tapers. If the nose angle is as per standard you can save work and just purchase a 25 collet closer.

Edited By Martin of Wick on 11/12/ 15:13:34

Hi Paul,

If you want to use your "special" ER 25 collets in an ordinary ER25 collet chuck with a MT or R8 shank you may be lucky and find a chuck that will accept your special collets. You will probably find that some machining is necessary, a carbide tipped tool should be up to the job. I have a slightly larger ER 32 chuck and it would be possible to make room for longer collets. If you want to use the collets for workholding in your lathe you could just make your own collet chuck. That is what I did for my small lathe, and the chuck is used quite often.

Thor

Edited By Thor on 11/12/ 15:37:40

Have you measured the angles? 30 degree front and 8 degree back. If not the same why not make your own holder to suit? Sounds as if an ER25 nut could be used as a closure if the front angle is 30 degree. Seems a pity to waste such a gift horse and if they are SKF manufactured they would/should be pretty good.

I happen to have some new er25 collets. They are 34mm long and at that length, the diameter is 19mm. This is the free diameter, and if you set calipers to 19mm and the diameter of yours is about that at 34mm from the front end, they might fit an er25 holder.

I tried googling Sandvik 393 collets and the result was very different from an er shape.

Edited By old mart on 11/12/ 15:36:22

I never even considered making a collet holder myself! i have a set of ER32 collets and holder for the mill but nothing for the lathe.

I will check the angles tomorrow and then try to think of a a way to make the useful on the lathe.

Thanks all for the suggestions.

Regards

Paul

Making a holder is fairly trivial, I made one successfully quite a few years back when I had very little idea what I was doing! (Not that I do now mind you&#;)

• Make a backplate to closely fit your spindle nose with a suitable spigot on the front on which to form the holder. Make sure it can go back in the same position on the nose so you can get repeatability in use.
• Set the topslide to the taper by chucking a bit of ground bar that's a close sliding fit in one of the collets, sliding on the collet, then using a DTI in the toolpost set the topslide to get a zero-zero reading on the tapered side of the rear taper (being careful to avoid one of the slit grooves).
• Mount the assembly on the spindle and turn the spigot to size, make the closer thread to suit a standard collet closer nut (of course this assumes that the front taper and groove suits)
• Bore out the spigot for the minimum diameter and bore the taper to fit the back collet taper. You're done!

I have some similar, came with 'multi machine (lathe/mill) I bought from a friend who was getting divorced (paid him same as he paid for machine, felt sorry for him)

It's closer to a Morse taper but doesn't match MT3

No idea what standard they are but interested in finding out

Edited By Peter Jones 20 on 11/12/ 18:19:34

The characters after the dash on the first line of the part number are the LETTERS 'O' (for orange) and 'Z' (for zebra).

If you put that part of the part number into Google, you get to:

https://www.sandvik.coromant.com/en-gb/products/pages/productdetails.aspx?c=393.01-oz%

which gives a reference of DIN.

They are likely OZ collets.

http://www.collet.com.tw/en/product-c/OZ-System.html

Big difference in the back taper angle for the EOC collet &#; 2.52 degree versus 8 degree for an ER &#; they must be high precision collets and are worthy of being used &#; even if you have to make a collet holder. As I said in my earlier post if the front angle is 30 degree then an ER25 nut may be a nailed on bet for a closure nut.

I think they could be EOC16 collets, the size looks right. **LINK**

Din is the classification, as DC31k says.

For more information, please visit Er Collet Types and Sizes.

Edited By old mart on 11/12/ 19:32:56

I think we have a winner!

The Spec says its a EOC16A collet, and the front angle is 30°

Since they are split from both ends, they will be flexible, like ER collets.

Being Sandvik, the quality will be good

If an ER clamp nut fits the front end, I would be tempted to make a collet holder for them, so that they can be used.

Not being skilled enough to make them, I buy my Clamp Nuts.

The pitch for ER Clamp Nut threads is 1.5 mm. I have made holders for ER collets for various jobs, (Tap holders, Collet Blocks, drll / end mill holders for grinding ). If I can do it, you surely can!

Howard

Vertex (available from Rotagrip) list OZ nuts in their catalogue. They probably sell a chuck as well if you look hard enough (OZ chucks are listed by SanTool in Germany).

http://www.rotagriponline.com/datasheets/Vertex36/C30.pdf

They are also known as ISO , so that might help in a search.

Edited By DC31k on 12/12/ 12:02:24

ER collets are essential tools in the machining and manufacturing industries, widely used for holding cutting tools or workpieces with high precision. Their versatility and reliability have made them a popular choice in various applications. In this blog, we&#;ll explore the capacity of the ER50 collet, how to determine ER collet sizes, the different collet sizes available, and the maximum size of an ER20 collet. We&#;ll also introduce Sikka Collets & Accessories, a trusted name in the industry, known for producing high-quality ER collets.

What is the Capacity of ER50?

The ER50 collet is one of the largest in the ER series and is designed to accommodate larger tools or workpieces. The capacity of an ER50 collet typically ranges from 13mm to 34mm. This wide range makes it suitable for holding a variety of tool sizes, providing a secure grip and minimizing runout during operation. The ER50 is ideal for heavy-duty applications where precision and stability are crucial.

How to Determine ER Collet Size?

Determining the appropriate ER collet size for your application is straightforward but essential for achieving the best results. The size of an ER collet is typically indicated by the diameter of the tool or workpiece it can hold. For instance, if you have a 12mm shank, you would choose an ER collet that can grip a 12mm diameter.

The process involves the following steps:

1. Identify the Tool Shank Diameter: Measure the diameter of the tool or workpiece you need to hold.

2. Select the Appropriate Collet Size: Choose a collet that has a clamping range encompassing your tool diameter.

3. Check the ER Collet Range: Ensure the selected ER collet size is compatible with your chuck and can securely hold the tool within its clamping range.

What are the Different Collet Sizes?

ER collets come in various sizes, each designed to accommodate different tool diameters. The common ER collet sizes include:

&#; ER11: Typically used for holding tools from 1mm to 7mm.

&#; ER16: Suitable for tools ranging from 1mm to 10mm.

&#; ER20: Designed for tools from 1mm to 13mm.

&#; ER25: Accommodates tools from 1mm to 16mm.

&#; ER32: Holds tools ranging from 2mm to 20mm.

&#; ER40: Suitable for tools from 3mm to 26mm.

&#; ER50: As mentioned, holds tools from 13mm to 34mm.

Each size offers different ranges, allowing machinists to select the perfect fit for their specific needs. The variety ensures compatibility with a wide range of machines and tools, making ER collets incredibly versatile.

What is the Maximum Size of ER20 Collet?

The ER20 collet is a popular choice due to its balance between size and versatility. The maximum size that an ER20 collet can accommodate is typically 13mm. This makes the ER20 collet ideal for medium-sized tools, offering a good balance between holding power and precision. It&#;s commonly used in milling, drilling, and CNC machining applications where moderate-sized tools are employed.

Sikka Collets & Accessories: Your Trusted Collets Manufacturer

When it comes to sourcing high-quality ER collets, Sikka Collets & Accessories stands out as a leading collets manufacturer. With a strong reputation in the industry, they offer a wide range of collets, including ER11 to ER50, ensuring that all your machining needs are met with precision and reliability.

Sikka Collets & Accessories is committed to delivering products that meet the highest standards of quality. Their ER collets are crafted with precision engineering, ensuring a tight grip, minimal runout, and long-lasting durability. Whether you&#;re looking for standard collets or custom solutions, Sikka provides excellent customer service and technical support to help you find the perfect collet for your application.

For machinists and manufacturers looking for reliable collets, Sikka Collets & Accessories is the go-to source for quality and performance. Their products ensure that you can achieve the precision and accuracy required in today&#;s competitive manufacturing environment.

Read Also &#; ER Collet Nuts,Wrenches And Spanners(DIN )

Conclusion

Understanding the capacity, sizing, and variations of ER collets is crucial for optimizing your machining operations. Whether you&#;re using an ER50 collet for heavy-duty tasks or an ER20 for moderate applications, selecting the right collet size is essential for precision and efficiency.

If you&#;re in the market for high-quality ER collets, consider Sikka Collets & Accessories, a trusted collets manufacturer known for its dedication to excellence and customer satisfaction. With their wide range of products, you can find the perfect collet to meet your specific needs, ensuring that your machining processes run smoothly and accurately.

For more Types of Er Colletsinformation, please contact us. We will provide professional answers.