How to Cut Locks

Cutting the Lock with Bolt Cutters

Use a pair of bolt cutters at least 24 in (61 cm) long. Visit your local hardware store to see their selection of bolt cutters. Aim to get cutters 24 inches (61 cm) long or larger since they will give you the most leverage as you try to cut through the lock. Larger pairs of bolt cutters can cut through locks with a larger diameter.

Put the lock’s shackle between the blades of the bolt cutters. Tilt the lock to the side so you can easily cut the side of the shackle, or the metal clasp that holds the lock together. Hold the bolt cutters in a comfortable position near your waist. Pull the handles apart so the blades open. Place the bolt cutters on one side of the shackle close to the body of the lock. If the lock isn’t attached to anything, secure it in locking pliers or a vise so it doesn’t move around when you try cutting it. Spin the handle on the vise to close it around the lock.

Squeeze the grips together to close the cutters. Hold the grips on your cutters and apply firm pressure to break through the lock. Squeeze the handles together until it cuts through the shackle. If you can’t cut through the lock yourself, ask a friend to help you close the bolt cutters. If the lock is made of hardened steel, bolt cutters may not work. Bolt cutters work best on padlocks or chained bike locks.

Grinding the Lock

Buy an angle grinder with a cut-off blade from your local hardware store. An angle grinder is a portable machine that uses a disc to cut metal and tile. Use a 60 grit disc that’s ⁄64 inch (1.2 mm) thick for the easiest way to cut through the lock’s shackle. Angle grinders work best on padlocks or bike locks. If you’re working at home, use an angle grinder that plugs into the wall. If you need to work somewhere without electricity or an outlet, buy a battery-powered grinder.

Wear gloves and a face shield to protect yourself from sparks. Get a safety shield that covers your entire face and use thick gloves meant for shop work. Wear a long-sleeved shirt and pants if you can for added protection. Make sure there are no flammable objects near you or in the room since a spark could ignite them. Keep a fire extinguisher nearby just in case.

Hold the bottom of the lock secure with vise-grips. Vise-grips are locking pliers that clamp onto an object. Open the vise-grips to the same width as the lock you’re trying to cut. Turn the spindle on the end of the vise-grips’ handle to lock it in place so the lock doesn’t move around. Use your non-dominant hand to tilt the lock to the side and hold it steady. Vise-grips can be purchased at your local hardware store. If you’re working in a shop, clamp the lock inside of a vise instead.

Cut through the top of the lock’s shackle using your angle grinder. Turn on the angle grinder and slowly press the disc onto the shackle. As you cut through the lock, the grinder will shoot off sparks. Keep firm pressure on the grinder so it works through the shackle. Once you finish your cut, turn off the grinder and remove the lock. The lock may be hot near the area you cut. Use gloves to handle it or let it cool down first.

Using Heat and a Hacksaw

Keep the lock sturdy with vise-grips. Grip the bottom of the lock with a pair of vise-grips. Tighten the nut on the handle to ensure the lock doesn’t move around while you’re holding it. Tilt the lock away from the object it’s attached to. Don’t use your bare hands to hold the lock since you could burn yourself.

Hold a lit propane torch to the shackle for about 3 minutes. Pick any location on the shackle to heat. Light the torch with a striker and turn the valve on the nozzle to make the flames into a tight cone. Hold the tip of the flame against the shackle until it turns red hot. Find an area on the shackle that you can easily maneuver a saw around. Work in a well-ventilated area away from flammable materials. Keep a fire extinguisher nearby in case there’s an accident.

Let the lock cool down for 2-3 minutes. After the lock is red hot, turn off the propane torch and let the shackle cool. Don’t dip the lock in water to cool it down, since this could strengthen the steel again.

Saw through the area you heated. Use a fine-toothed hacksaw meant for cutting through metal. Hold the lock in place with vise-grips in your non-dominant hand, and pull the back and forth across the area you heated with your dominant hand. Apply firm pressure to the lock to cut through it completely. The heat softens the metal and helps the saw teeth stay in place as you try to cut the lock. Hacksaws work best on metal locks.