How to Use and Clean an ER Collet

Choosing the correct size for ER collets is critical in doing your work correctly. It’s true that a poor workman blames his tools but it’s difficult to be a good workman if you don’t even have the things. For example, if you use drills for certain jobs, it’s a good idea to have the right drill bits. Make sure that each tool has all the parts that it needs in order for you to be able to get the job done correctly. This is no different for ER collets. Here is a guide to help you choose the right one.

1. The first thing to think about needs to be the size of the end mills that you use the most. For smaller jobs, a smaller diameter range collet would work just fine. ER16 and ER32 sizes are the most common for smaller diameter ranges. ER20 is a good mid range size. These are probably the most popular and easiest to find. There are other sizes of course and you might prefer them. You just have to try things out to find your preferred one within the sizes.




2. The second thing to think about is how far you need to reach. This is referring to projection diameter. Usually a stubbier reach is better for reach L1 but you will have to make sure you do the research and take a look at the different parts that you need to run on the machine. You might need to use a holder in order to be able to reach a tight fit. If you don’t consider this properly then you might end up with a carbide shanked end mill that is too long. Smaller diameter ER collets are a lot cheaper over the course of the job.

Once you have all of the right tools you want to make sure that you take care of them properly. Collets need to be changed out if there are any scoring marks, rust or pit that you find. Using the correct collet for a job and doing regular maintenace on your collets can make all the difference when it comes to how long they last.

The nice thing about ER collets is that they are not expensive. Pretty much anyone can afford them. As long as you are not trying to do something extremely heavy duty or on super high RPMs then they can do a really good job. If they have run out, this will be better for them than setscrew holders. Having a low run out is important to the shelf life of the tool. You do want to make sure that your collet has a high quality finish on it in order to maximize the stiffness of the tool.

The main part of maintenance is just keeping it clean. Even the smallest of chips can make a huge amount of run out if it gets stuck in the collet, chuck nut or interior. It could also stop the college from gripping on to the shank efficiently enough. Any residue or oil could affect the holding power of the collet very quickly. Before assembling the tool, make sure that you douse the parts in degreaser in order to make sure that all the components are 100% oil free and dry as a bone. Degreasing helps out a lot. There were tests ran that showed that the difference on a shank that was clean and dry went from 1850 lb to 3600 lb. That should be enough to make you want to clean your tool! Even if you get a tool brand new, you should still degrease it. The reason for this is that many collets that are shipped will have some sort of protective grease on it so that it doesn’t get scratched or beat up during transport. Set up a sort of ‘welcome home’ procedure that you use on every tool before you try and use them for your work.

Most ER collets are cheap but if you want to spend even less, you could actually mix and match the collet chuck and the set screw holders. Just make sure you be careful to make sure they don’t slip during usage.