If the item is not so valuable you can use a padlock with a lower security level.
If the item is valuable you should buy a padlock with a higher security level.
Define the usage of your padlock – indoor, outdoor or travel-high security or low security.
Check if the padlock chosen matches the required performance of the padlock.
Please notice that size alone is not the only indicator to choose the right padlock,it needs to have the right security level to match its purpose.
Check to make sure the shackle will fit into the item you would like to secure.
The padlock should be the appropriate size for the required usage.
Check additional padlock features like shackle size, diameter & material, body material & finish and to match the surrounding components and area.
Short or long shackle size? The shackle size depends on the usage of the padlock. To pass through hasps and fittings with a long distance, a long shackle is required.
Additionally the diameter and material of the shackle are further points to take into consideration for better security. Please pay attention to the shackle diameter and that it matches into the desired hole for locking.
The purpose of the padlock body is to protect the lock system against attacks.
The main body types are Solid Brass, Laminated Steel and Armored Encased Brass.
Solid Brass: Brass is a softer metal and for producers cheaper to machine, thereby lower prices for customers. But these padlocks are susceptible to drill attacks and usually they have sharp corners which can scratch surfaces and objects they touch.
Laminated Steel: The body of this type is designed from separate thin steel plates which are riveted together. Lower production costs enable lower prices for the customers.
Armored Encased Brass: The brass body is encased in hardened steel for a better protection against drilling attacks and for providing a higher security level.
If you need more padlocks that can be locked and unlocked with a single key, you should use "Keyed Alike" padlocks.
If many people would like to share one padlock, you can use a combination padlock. The advantage is that you do not need many keys for lots of people. Please notice that combination padlocks are suitable for applications with a lower security level.