How to Measure a Padlock

When buying new padlocks or replacing old padlocks, the size of the lock is important to the overall security of the lock, this page will guide you through the important measurements of a padlock.

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Brass / Cylinder Padlock	Straight Shackle Padlock
Discus Padlock	Lever Padlock

A - Body Width
B - Body Height
C - Horizontal Clearance
D - Vertical Clearance
E - Shackle Diameter
F - Body Depth

As padlocks are available in a number of styles, brass, straight, round and lever padlocks, people are often confused about the best method of measurement.  However as the above diagram shows, each type of padlock is measured in the same way.

When measuring any padlock the two most important sizes to take is the body width and shackle diameter.  These two sizes will determine if the padlock will fit into the desired location.  Shackle diameter is by far the most important, as a shackle that is wider than the hole it is to go through is useless, just in the same way that a very narrow shackle padlock will not effectively secure a hasp with a much larger hole.

Other critical measurements to check are the horizontal and vertical clearance, these will determine the size of the chain or hasp that can be used with the padlock, these sizes become even more important when using a closed shackle padlock.