I.Iron padlockHow to open without a key
Most padlocks have a locking mechanism with a central spindle. This spindle has several holes, which correspond to similar holes in the lock body. Inside these holes, you can place a spring and two differently sized metal balls. When the key is inserted, the different tooth configurations cause the two balls to be pushed to different heights. If the positions of the two balls within the holes coincide with the circumference of the spindle, the spindle can rotate within the lock body, and the lock opens. This is the basic working principle of most padlocks. If the key to a padlock is lost, a universal key can be purchased. Universal keys can open a variety of padlocks.

Two. How to open a lock without damaging it.
1、Clamps are typically made from the wire used in paper clips. This wire is thin and strong, making it resistant to bending. These clamps are readily available in stationery stores and bookstores for a low price, typically a few cents each. Select clamps with appropriate thickness and length based on the size of the lock.
2. Remove the steel wire from the clamp. First, straighten the steel wire using pliers, then bend one end of the wire at a 135-degree angle, with a length of approximately 5 millimeters. The angle can be adjusted appropriately based on the thickness of the lock.
3. Bend the other end of the wire into a 90-degree angle. The length left is unrestricted, making it easier to use the wire to turn the lock with your hand.
4、once the wire is prepared, insert it deeply into the lock mechanism, approaching the narrower side. Continue inserting until you feel it is fully seated. The criteria for determining when the wire is fully inserted: After fully inserted, you should be able to gently rotate the wire and also hear the internal spring of the lock moving.
5. After inserting the wire, turn the wire counterclockwise. If the internal spring is dislodged, the lock tongue will retract within the lock, and the lock will be opened.
6. Generally, using this method carefully will not damage the lock.