A Complete Guide to Parts of a Combination Padlock

A combination padlock is a great way to secure a great number of different items. Bike locks, lockers, chains, fences, toolboxes, latches, and other important items can all be secured with a simple combination padlock. These locks have been around for quite a long time and are basically smaller versions of safe locks. Opened by the use of a predetermined combination of numbers, this padlock has been a favorite lock for a long period of time. How does a combination lock work? Here is a little guide to help better understand the different parts of a combination padlock.

Shackle or Hasp

This is the part of the lock that is curved and goes around the loops of a chain or clasp. It is usually made out of hardened steel and are very hard to cut with a bolt cutter or hacksaw. Some cheaper models of combination locks keep their prices low by using lower quality steel in the hasp.

Lock Case

The case is more than just a place to house the internal mechanisms. The quality of the steel is also a security measure that protects the lock from being broken by a hammer or other blunt force. 


The first thing that you think of when you talk about a combination padlock is the dial on the front of the lock. This dial can be either circular or a combination of thumb screws that correspond to different numbers. Along the face of a rounded dial are numbers from 0 to 59. You turn this dial to set the tumblers inside into their proper position. It is usually a combination of left turns, right turns, and then left turns. 


Housed inside the combination lock are the different tumblers. These tumblers are mounted on a cam that is turned each time the dial is moved. A tumbler is matched with a corresponding position of the dial. However, the tumbler is also set to line up when the dial is set to a specific number going in a specific direction. This is what causes a lot of frustration when remembering combinations. If you do not turn it in the right direction, the specified number of times, to the right number, the lock will not open. 


This is the part of the lock that you can see when you look down into the locking area. The small hole that the hasp goes into is where the dogs are located. You will see that they are shaped in the form of levers and catches. When the hasp is pushed into the locking hole, the dogs react and hold fast the hasp so that it can not be removed. When the tumblers are in alignment with the correct combination, then the dogs are removed and the hasp is free. 

Keyed Entry

Located on the back of most combination padlocks is a keyed area. This works in the same way a regular keyed lock works. The tumblers are also connected to this key so that when the right key is inserted they are aligned. Whenever you forget your combination you can use this key to unlock the padlock. However, the combination can not be reset, so unless you remember the combination you will need a new lock.