Padlocks provide portable security for movable items such as bikes and boats and in locations such as lockers and outdoor sheds. Although weatherproof construction is important, high security is important to protect expensive equipment. Pin-tumbler padlocks provide maximum security for valuables and laminated types are nearly unbreakable. The type of metal used in construction is important to consider. Hardened solid steel and steel alloys make better locks and shackles; solid brass is more resistant to rust than steel but can be damaged because it is softer than steel. Pin-tumbler locking mechanisms make padlocks harder to pick. Four-pin-tumbler mechanisms provide enough security for most uses and padlocks with five or more pin tumblers offer more security and are more secure than combination locks.
Warded padlocks are a low cost alternative but do not provide as strong security. They offer superior weather resistance because of the lack of rotating internal parts and their simple construction.
Use a padlock through the bolt in a hasp for added security. Hasps consist of a metal hinge and a anchoring bolt in order for them to be secured to gates, sheds, and garages. High-security hasps have anchored eyebolts, pinless hinges, hardened steel anchoring loops and hidden screws.