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How to use a FLEX angle grinder

Updated: October 2026

The disc is still on the spindle from the last job, and you want it off before you cut a bracket or grind a weld. How to use a FLEX angle grinder starts with the power off, then the guard that matches the job, then a disc rated for the tool. Prices for the six listings are on the [Flex angle grinder comparison](/hub/tools/flex-angle-grinder). The Products Compared editorial team used Electrical Safety First, the OPSS alert PSA5, and the saved listings on 21 October 2026. We did not run a disc up in a lab. A qualifying purchase can earn us a commission at no extra cost to you.

The disc is still on the spindle from the last job, and you want it off before you cut a bracket or grind a weld.

Our top picks

Flex Flex LBE 76 12-EC C

Best overall

Flex Flex LBE 76 12-EC C
3.7/10about £136.44
View offer
Flex Flex L 1100 125

Best value

Flex Flex L 1100 125
7.4/10about £75.00
View offer
Flex Flex L 12-11 125

Rank 3

Flex Flex L 12-11 125
8.4/10about £166.04
View offer
On this page
  1. 1.Unplug, or take the pack off
  2. 2.Guard and spindle lock
  3. 3.Disc rating and the toothed-blade ban
  4. 4.Stance, and when to stop

Unplug, or take the pack off

Electrical Safety First says to unplug before you touch the wheel, and to use a UK 3-pin plug rather than an adaptor. That covers the L 1100 125, the L 12-11 125, the L 13-10 125-EC, and orders 534016 and 534017. None of them is a 110 V site tool. On the LBE 76, take a fitted pack off on the bench. Order 531717's included line does not name a pack.

Guard and spindle lock

The family manual for the L 12-11 uses a cutting guard for cutting. Only order 532609 prints a tool-less cover, and that manual bars a diamond cup on the L 12-11. The LBE 76 bullets include a cut-off hood. A 125 mm grinding guard will not bolt across. Hold a spindle lock only after the power is off. Which cell is which is on the FLEX angle grinder buying guide.
Flex Flex LBE 76 12-EC C

Testsieger

Flex Flex LBE 76 12-EC C
3.7/10about £136.44
View offer

Disc rating and the toothed-blade ban

Match the disc to the printed speed: 11,500 rpm on the L 12-11, 10,000 on the L 13-10, 11,000 maximum on order 534016, and 20,000 maximum on the LBE 76. Order 534017 and the L 1100 do not print rpm. Do not borrow a figure from the next row. Order 534016's dial still needs a disc rated for 11,000 rpm. Run a new disc for at least 30 seconds, clear of the disc plane. The stop-time claim is on FLEX angle grinder with brake.

Stance, and when to stop

Use both hands. One Germany review calls the L 1100 very heavy, and the weight cell says 3.16 kg. If the side handle is missing, do not start. Stand out of the disc plane, and let the tool reach speed before it meets the metal. On the mini, FLEX states a cut of about 22 mm. Stop if the housing has smoked, if the job is structural or a 230 mm disc, or if you are mounting wheels at work without training.

Common questions

Do I unplug a corded FLEX before the disc comes off?
Yes. Electrical Safety First says to unplug an angle grinder before you touch the wheel. That covers the five corded listings here, from the L 1100 125 at £75.00 to order 534016 at £286.76. Do it before the guard moves and before the flange spanner comes out. A restart lock, where the listing prints one, is not a substitute for pulling the plug.
What replaces the plug on the 12 V mini?
You remove the pack. The LBE 76 manual says to take the battery off before work on the tool. The amazon row at £136.44 does not name a pack in the included line, so this applies when a pack is fitted, not as proof one was in the box. Unplugging a lead you do not have will leave the pack on the tool.
Is a grinding guard the right hood for a cut?
No. The family manual that covers the L 12-11 uses a cutting guard for cutting. A grinding hood leaves more of the disc open. Only the L 1100 listing prints a tool-less guard, and the mini's bullets include a cut-off hood. If your row does not mention a guard, do not assume the carton has the hood you need for a cut-off disc.
May I fit a toothed wood blade?
No. OPSS alert PSA5 says to stop using toothed saw blades and chainsaw-type discs on angle grinders. The warning it points to, under the Supply of Machinery (Safety) Regulations 2008, is not to fit a saw-chain woodcarving blade or a toothed saw blade. A maker line about cutting wood or plastic with the mini is not that blade.
Does anti-kickback mean I can skip the guard?
No. On the L 12-11 the bullet means the motor turns off if the disc blocks. On orders 534016 and 534017, anti-kickback is printed as well as a 3.5-second brake. Neither line replaces the guard, both hands, or a disc rated for the tool's maximum speed. The L 1100 and the L 13-10 do not print an anti-kickback bullet at all.
Which of these listings actually say spindle lock?
Only the L 1100 125, order 532609. The bullets on that £75.00 listing say spindle lock, next to a tool-less guard. The L 12-11, the L 13-10, both 2,000 W orders, and the LBE 76 do not print the words. If your tool has a lock, use it only after the plug or the pack is off. Do not borrow a pin-spanner sequence from a different FLEX manual.
What if the switch will not start after a power cut?
If that listing prints a restart lock or a reset lock, switch the tool off and back on after the power returns. Orders 532609, 447676, 534016, and 534017 print that feature. It is not a repair. If it still will not start, leave the disc fitted and get the tool checked. One Germany review of the L 12-11 describes a no-start after a year that the seller repaired.

Related pages

Corded or 12 V flex angle grinder

Best Flex angle grinder UK

Flex angle grinder

Flex angle grinder brake: stop time, not a cut-out

Flex angle grinder buying guide: disc class and supply

Sources

Public sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the six amazon.co.uk listings captured on 21 October 2026. A manufacturer page does not fill an empty amazon cell. PUWER 1998 applies at work. It is not a certificate for a domestic grinder.

  1. Flex, brand history (retrieved 21 October 2026)
  2. Flex, L 12-11 125 (retrieved 21 October 2026)
  3. Flex, L 13-10 125-EC (retrieved 21 October 2026)
  4. Flex UK, LBE 76 12-EC C (retrieved 21 October 2026)
  5. Toolstation, angle grinder buying guide (retrieved 21 October 2026)
  6. HSE, PUWER overview (retrieved 21 October 2026)
  7. Electrical Safety First, angle grinders (retrieved 21 October 2026)
  8. OPSS, PSA5 toothed blades (retrieved 21 October 2026)