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How to use a Dremel

Updated: October 2026

The nose cap is still tight, and you would like the bit to stay in the collet. This is how to use a Dremel when the tool in your hand is an EZ Twist model such as the 3000, the 4250 or the 8240. The sequence is from Dremel's own instructions. If your kit uses a wrench or a neck lock, follow that listing instead of forcing this sequence onto it. Which of the twelve to buy stays on our [Dremel multi tool comparison](/hub/lawn-and-garden-equipment/dremel-multi-tool) and on the [Dremel multi tool buying guide](/hub/lawn-and-garden-equipment/dremel-multi-tool/sub/dremel-multi-tool-buying-guide). A qualifying purchase can earn a commission at no extra cost to you. The notes follow the 22 October 2026 listings.

The nose cap is still tight, and you would like the bit to stay in the collet. This is how to use a Dremel when the tool in your hand is an EZ Twist model such as the 3000, the 4250 or the 8240.

Our top picks

Dremel Dremel 3000 130 W

Best overall

Dremel Dremel 3000 130 W
9.2/10about £44.00
View offer
Dremel Dremel 8240 12 V

Alternative

Dremel Dremel 8240 12 V
9.2/10about £119.95
View offer
DEKOPRO DEKOPRO 170 W kit

Best value

DEKOPRO DEKOPRO 170 W kit
8.6/10about £29.99
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On this page
  1. 1.Before the switch
  2. 2.Change the bit
  3. 3.Speed
  4. 4.When to stop

Before the switch

Unplug a corded tool before you change a bit. On the 8240, turn the tool off. Do not press the shaft lock while the shaft is spinning. Press the lock and turn the shaft by hand until it engages. The 8150 pack does not slide off, so off means the switch. At work, the Health and Safety Executive expects safety spectacles, goggles or a face screen when the risk assessment says so. At home the grit is the same. A 4250 reviewer asked for a respirator as well as eye protection because of the dust. Clamp the workpiece rather than holding a small fitting in your fingers.

Change the bit

On an EZ Twist Dremel the nose cap is the wrench. Turn it anticlockwise to loosen the collet nut, seat the new shank fully, tighten, and refit the cap. A shank that is only halfway in will creep out at speed. Try a gentle tug with the power still off. Dremel's UK sizes are 0.8, 1.6, 2.4 and 3.2 mm, and most accessories are 3.2 mm. Many kits include only the 3.2 mm collet. A 1 mm jewellery drill will not grip in that collet. Buy the matching collet. Do not push a larger shank into a smaller one. EZ SpeedClic is a separate disc mandrel, not the nose cap.
Dremel Dremel 3000 130 W

Testsieger

Dremel Dremel 3000 130 W
9.2/10about £44.00
View offer

Speed

Try a scrap piece, as Dremel's quick-start guide says. Wood and steel cutting are put at high speed in the 8240 instructions. Plastics that melt are put slower. If the edge smears, you are too fast or you are dwelling. More pressure loads the disc and makes a thin wheel wander. Wire brushes on the 8240 must not exceed 15,000 rpm, and felt polishing stays at 15,000 rpm or less. The 3000's floor is 10,000 rpm. The 4250 field starts at 5,000 rpm, though one highlight on the about £80.00 listing also says 10,000 rpm. Read the accessory, not the maximum on the housing.

When to stop

Stop when you smell hot plastic or hot windings, when a disc is cracked, or when the tool has smoked. A swollen battery is not a DIY opening-up job. Unplug it or isolate the pack and use the seller's return route. Stop and get a professional for a structural cut, for a hidden cable or pipe, or for a chainsaw chain or a damaged mower blade you are not set up to sharpen. A rotary stone on a garden shear is a smaller job. One 4250 review of a stop after about four hours is a single report, not a service interval.

Common questions

How do I change a bit on a Dremel?
On an EZ Twist model, unplug or switch off, press the shaft lock and turn the shaft by hand until it locks, then use the nose cap as the wrench. Turn anticlockwise to loosen, seat the new shank fully, tighten, and refit the cap. Do not press the lock while the tool is running. The 8240 instructions say the same idea: power off before the change.
Do I unplug first?
Yes on a corded 3000 or 4250. The manuals say unplug before a collet change. On the 8240, turn the tool off before you change the bit. Remove a pack when the tool allows it. The 8150 battery is integrated, so you cannot pocket the pack, and one review says that tool will not run while it is charging. Either way, the shaft is stopped before the lock button is used.
What collet is already in the tool?
Often only 3.2 mm, which fits most Dremel accessories. The maker also sells 0.8, 1.6 and 2.4 mm collets. If a fine drill spins inside the nut or will not enter, you have the wrong size, not a faulty motor. Seat the shank fully. A shank that is half inserted will walk out at speed.
Why will the accessory not grip?
The shank and the collet do not match, the shank is not fully home, or the nut is cross-threaded. Third-party bits are a common reason 3000 owners buy another collet or a multi-chuck. On the GALAX PRO kit, one review says the supplied bits did not fit the supplied collets. Do not force a larger shank into a smaller collet, and do not grind the shank down to make it fit.
What speed for wood, plastic and steel?
Dremel's 8240 instructions put wood and steel cutting at high speed and plastics that melt at a slower speed. Wire brushes must not exceed 15,000 rpm, and felt polishing stays at 15,000 rpm or less. Try a scrap of the same material first. If the plastic smears, reduce speed and ease off the pressure. More force is not the fix for a poor cut.
Can I lean on a cutting disc?
No. Let the disc cut. Leaning on it heats the workpiece, bends a thin wheel and makes a slip more likely. If nothing is happening, the disc may be glazed, the speed may be wrong, or the material may be beyond a hobby wheel. Stop and change the accessory rather than adding body weight. A cracked disc is finished.

Related pages

Dremel corded or cordless

Dremel for model making

Dremel multi tool

Best Dremel rotary tool UK for the long review line

Dremel multi tool buying guide: job, cable and shank

Sources

Sources from the research digest, last checked on 22 October 2026. Shelf prices and star lines are the amazon.co.uk listings captured on 22 October 2026.

  1. amazon.co.uk listings for the twelve tools in this set (retrieved 22 October 2026)
  2. Dremel GB, 3000 (retrieved 22 October 2026)
  3. Dremel GB, Lite F0137760JB (retrieved 22 October 2026)
  4. Dremel GB, collets 3.2 mm (retrieved 22 October 2026)
  5. Dremel UK quick-start guide (retrieved 22 October 2026)
  6. HSE, Hand-arm vibration regulations (retrieved 22 October 2026)
  7. HSE, Assess the risks from hand-arm vibration (retrieved 22 October 2026)
  8. Consumer Rights Act 2015, section 9 (retrieved 22 October 2026)