If you work with Dremel’s or other rotary tools, you’ll have heard about collets and chucks. But what are they, which should you use and when.
What are collets
Three Dremel collets for different bit shaft sizes*.
Collets work like collars that grip your tool bit. You slide the collet into the Dremel and screw on a collet nut that tightens around it to grip the tool. They have a lot of contact points with the bit and can maintain a strong grip even at high speeds. (With a rotary tool like the Dremel 3000 which spins its bits at between 3,000 and 40,000 RPM, this is obviously important).
Two bits with different shaft diameters, and two different collets will be needed.
The downside however is that changing the bits takes a little time, especially if you’re changing between collet sizes for bits with different diameter shanks. The typical Dremel bit has a shaft diameter of 1/8 inches (3.2mm) but other tools with other diameters are common (as in the above photo) and for each, you’ll need a different size collet and swap between them when using the different bits.
Changing collets isn’t difficult. Undo the collet nut with the wrench, swap the collet, put the nut back on, insert the bit and retighten the nut. It doesn’t take long but doing this repeatedly gets boring and slows down your work. The video below how this is done.
What are chucks
The Dremel keyless chuck, ideal for when using several bits with different shaft diameters*
Chucks, on the other hand, use mechanical jaws to hold the bit in place. On larger drills, chucks often have a key that is inserted into the chuck to tighten and loosen it whereas Dremel has a keyless variety that can be just twisted.
Unlike the fixed-sized collets, chucks can hold different bit shaft thicknesses so can handle a range of bits without needing to switch to collets (from 1/32” – 0.8mm to 1/8” – 3.2mm). When you’re using a lot of bits or using a few different diameter bits, the keyless chuck is much quicker and easier to work with, as the video below demonstrates.
Collet or chuck – which to use
When deciding which tool holder to use, think and how often you need to switch out your bits, particularly where they have different shaft diameters. If you plan on using several bits of different shaft sizes in a session, you’ll also need to change collets each time so a chuck may be easier and quicker to work with.
But also consider the type of work you’ll be doing. A collet, with more points of contact, will provide a better grip strength, important if you need to use the same bit for an extended period, whereas a chuck can hold larger diameter bits.
For precision work on my models and trains, I tend to use collet but for general usage and DIY work around the house the keyless chuck is quicker and easier.
Let me know what you prefer with a comment below.
To order chuck or collets:
> Get the Dremel keyless chuck here.
> Get the Dremel collet set here.
- In use, install the bits with 1/4″ between the Dremel nose cap and the bottom of the working part of the bit; here I’ve left it protruding further so the collet nut and chuck can be clearly seen.
Andy is a lifelong modeler, writer, and founder of modelrailwayengineer.com. He has been building model railways, dioramas, and miniatures for over 20 years. His passion for model making and railways began when he was a child, building his first layout at the age of seven.
Andy’s particular passion is making scenery and structures in 4mm scale, which he sells commercially. He is particularly interested in modelling the railways of South West England during the late Victorian/early Edwardian era, although he also enjoys making sci-fi and fantasy figures and dioramas. His website has won several awards, and he is a member of MERG (Model Railway Electronics Group) and the 009 Society.
When not making models, Andy lives in Surrey with his wife and teenage son. Other interests include history, science fiction, photography, and programming. Read more about Andy.