How To Drill Out A Lock

Drilling out a lock becomes necessary when the internal mechanism fails and the door cannot be opened through normal operation. Lost keys, snapped keys inside the cylinder or worn internal pins can all prevent the lock from turning. In these situations, drilling removes the internal pin stacks so the cylinder plug can rotate and the door can open. Because this process destroys the lock barrel, it should only be considered when other access methods are not possible. Before attempting to drill a lock, confirm the problem cannot be solved with a spare key, lock lubrication or basic troubleshooting.

Professional locksmiths rarely begin by drilling. They usually attempt non-destructive entry methods first, such as lock picking, decoding the cylinder or bypassing the mechanism using specialist tools. These approaches preserve the lock and avoid unnecessary lock barrel replacement. Drilling becomes the final option when the cylinder is seized, damaged or designed in a way that prevents the lock from being opened normally.

 

You may need to drill a lock when:

• A key has snapped inside the lock and cannot be safely extracted.

• Internal pins or springs have failed and the cylinder will not turn.

• The lock has seized due to corrosion, debris or mechanical wear.

• A euro cylinder lock has failed and the cam cannot retract to open the door.

• The cylinder must be removed to complete a lock barrel replacement.

Identifying drillable locks vs. anti-drill locks

Before you attempt to drill a cylinder, identify the lock type first. Many UK doors use euro profile cylinders, especially on uPVC and composite doors, and you’ll see a wide range of euro cylinder locks in this format. Standard cylinders may be more vulnerable when the internal mechanism fails, but some modern cylinder locks include anti-drill protection that makes DIY drilling impractical. 

Look for security markings, kitemarks, star ratings and manufacturer claims such as anti-drill, anti-pick or anti-snap. High-security cylinders may also use hardened steel inserts or reinforced face sections around the keyway. If the lock appears heavily reinforced or carries clear high-security markings, stop and consider professional help instead.

 

Signs a lock may include anti-drill protection:

• Anti-drill wording on the cylinder or product paperwork.

• TS007 star ratings or other security certification marks.

• Manufacturer branding associated with higher-security cylinders.

• Reinforced metal around the keyway or face of the cylinder.

Drilling a euro cylinder lock requires patience and careful control. The goal is not to force the door open but to destroy the internal pins so the cylinder can rotate and release the lock. Most euro cylinders contain a row of spring-loaded pins aligned along a shear line. When a key turns correctly, those pins line up and allow the plug to rotate. Drilling targets that pin stack so the mechanism can no longer block movement. Accuracy matters because drilling too high or too low can damage the cylinder body or door hardware without clearing the pins. 

Before starting, confirm the lock is not a high-security or anti-drill model and gather the correct drill bits and safety equipment. Once the internal pins have been cleared, the lock barrel can usually be turned with a screwdriver and removed before fitting a replacement cylinder. Replacement parts are widely available within euro cylinder locks and other compatible cylinder locks, allowing you to restore the door quickly once the damaged barrel has been removed.

• Insert a centre punch just above the keyway where the pins sit along the shear line. Tap lightly to create a small indentation that guides the drill bit.

• Start with a small drill bit (around 3mm) and drill slowly into the pin chamber. Maintain steady pressure and keep the drill level with the cylinder face.

• Gradually increase the drill bit size to around 5–6mm. This removes the pin stacks that prevent the plug from rotating.

• Keep the drill aligned and avoid forcing the bit. Let the drill cut steadily through the metal rather than pushing aggressively.

• Once the pins have been destroyed, insert a flat-head screwdriver into the keyway and turn the plug as if using a key to open the lock.

Preparing the lock and workspace

• Clear the area around the door so you can work safely without slipping or bumping the drill.

• Open the door if possible, or stabilise it firmly so it cannot move while drilling. Movement can cause the drill bit to slip across the cylinder face.

• Wipe the lock face clean so you can clearly see the keyway and cylinder outline. Dirt or debris can interfere with accurate drilling.

• Identify the shear line position just above the keyway where the pin stacks sit inside the cylinder.

• Use a centre punch and light hammer tap to create a guide mark before drilling. This prevents the drill bit from wandering across the lock surface.

Precision drilling techniques for effective removal

• Start with a small pilot hole using an HSS bit, keeping the drill square to the cylinder face and the pressure steady. Accuracy matters more than force at this stage.

• Drill at a controlled, medium speed so the bit cuts cleanly rather than skidding across the lock face or overheating.

• Increase bit size gradually to widen the hole and clear the pin stacks at the shear line. Do not jump straight to a larger bit, as that makes the drill harder to control.

• Keep the bit aligned with the cylinder and let it cut at its own pace. Forcing the drill can snap the bit or damage surrounding hardware.

• Stop regularly to check progress and clear swarf from the drilling point. If the bit makes little progress or the lock appears reinforced, stop and reconsider the approach.

• Once the cylinder no longer binds internally, test the plug carefully with a screwdriver to confirm it will turn.

Post-drilling actions and lock barrel replacement

Once the cylinder has released, clear away loose swarf from the keyway and the face of the lock so debris does not interfere with removal or fitting. Keep the cam aligned while removing the damaged barrel, then check the old cylinder size before fitting the replacement. To change a uPVC door lock, measure from the centre screw hole to each end of the barrel so the new cylinder sits flush and operates correctly.

• Turn the plug with a screwdriver until the cam aligns with the cylinder body.

• Remove the retaining screw from the edge of the door.

• Slide the damaged barrel out carefully.

• Measure from the centre fixing hole to each end of the old cylinder.

• Fit the replacement cylinder, align the cam and tighten the retaining screw.

• Test the new lock fully before closing the door.