Turns out, any Master Lock can easily be broken into with just a small hammer. As this video illustrates, all you need to do is tap the side of a Master Lock with a hammer to get it to open, no key, no combination required.
Pick the Lock Using Bobby Pins
Start by inserting the closed "looped" side of one bobby pin into the bottom portion of the lock. Use the second bobby pin, broken in half, toward the top of the lock and move it back and forth. This motion should set the pins and cause the deadbolt to unlock.
One of the easiest ways to break a padlock is with a hammer. Start by inserting 2 fingers into the padlock's shackle loop and pull up on the shackle to create tension. Then, tap the side of the lock that contains the fixed end of the shackle with a hammer using quick, short strikes.
Unfortunately, you can not unlock a deadbolt with a credit card. Credit cards will only work with slanted-latch-style locks. Furthermore, the slant of the latch must be facing you so that you may press it in using your card.
A technique known as "lock bumping" was first classified as a security concern around 2002. To bump a lock, a burglar inserts a specially cut key into the lock, then gently “bumps” it with a mallet or a screwdriver. This forces the pins in the lock to the shear line as the key turns and the door opens.
A hammer. As rudimentary as it may seem, a hammer to the door handle can be an effective way of gaining entry, This technique takes a bit more muscle and a trip to the hardware store for a new handle ($10). Bash that sucker down until the screw mechanism breaks on the inside. The door should swing right open.
To unlock a privacy lock you'll need a flathead screwdriver that is small enough to fit into the hole on the doorknob. Insert your screwdriver into the hole and push forward. If your doorknob is using a push-button type privacy lock, then you should hear a loud click and the door will open.
Picking a Locked Bathroom or Bedroom Door Lock
Most interior locksets have a pinhole on the outside knob for emergencies. All you need to pick one of these locks is a single straightened-out paper clip to substitute for the pinhole door knob key. Insert the paper clip into the pinhole and push on it to unlock the door.
It's quite easy to pick a deadbolt lock. In fact, you would want to replace all your key locks with electronic ones when you discover how simple it is. This doesn't mean that picking a deadbolt lock does not require skills or practice – it still does – but the technique is so easy that anybody can learn it.
Generally speaking, deadbolts are sturdy locks that can withstand kick in and other forced entry attempts. However, a door with a deadbolt can still be kicked down if the door itself is not solid. So, to protect your door against kick in, you want to make sure both the lock and door are of high-quality grade.
Start by pulling the bobby pin apart and roughly straightening it as such. Next, stick the straight end of the hairpin about one centimeter, or about 1/3 of an inch, into the keyhole of your lock and apply enough pressure to bend the end of the pin into a hook. The result should look something similar to this.
Bolt cutters are the common tool of choice for to cut padlocks during forcible-entry. Unfortunately, most padlocks are made of case-hardened steel, which is very strong in comparison to the materials that bolt cutters were intended to cut.
Try bolt cutters.
This will not work on most master locks, as they are made of case hardened steel.