For added security, locks have specially designed keys that cannot be duplicated and cannot be removed when the lock is open. Choose these locks if you need several locks that open with the same key.

Stainless steel-body lock is stronger and more corrosion resistant than brass-body locks. It has a concealed shackle to make it more difficult to cut.

Stainless steel shackles are more corrosion resistant than hardened steel shackles, but not as strong.

Disc-tumbler key locking mechanisms offer good pick resistance. When choosing between padlocks with seven or eleven discs, the lock with eleven discs is harder to pick.

Shackle is concealed to make it difficult to cut. Choose these locks if you need several locks that open with the same key. If the lock or key with the key number you want isn’t listed, order the "Other Key Numbers" and specify your desired key number.

Pin-tumbler key locking mechanisms are difficult to pick. Bump-resistant cylinders with pin-tumbler mechanisms are the most tamper resistant—they have a tapered top pin that stays put to prevent unlocking when a tool is tapped into the lock.

Shackle is concealed to make it difficult to cut. Choose these locks if you want individual locks or groups of locks that open with their own key, but also open with a master key. The included keys have random key numbers; master keys are sold separately.

Steel-body locks have a plastic cover to provide corrosion resistance. Stainless steel-body locks are more corrosion resistant than steel-body locks, but are not as strong.

Stainless steel shackles are more corrosion resistant than hardened steel shackles, but are not as strong.

Pin-tumbler key locking mechanisms are the most difficult locking mechanisms to pick. When choosing between padlocks with four or five pins, the lock with five pins is harder to pick.

Shackle is concealed to make it difficult to cut. Set your own combination and change it at any time.

Hardened steel-body lock is stronger than brass-body lock and epoxy coated to provide corrosion resistance.

Brass-body lock is more corrosion resistant than hardened steel-body lock. It also has a boron carbide shackle, which is harder and more corrosion resistant than a hardened steel shackle.

Choose these locks if you need several locks that open with the same key. Also called hockey puck locks, these eliminate the most vulnerable part of any padlock—the shackle.

Choose these locks if you want individual locks or groups of locks that open with their own key, but also open with a master key. All of these locks have random key numbers; they also open with a master key (sold separately). Also called hockey puck locks, these eliminate the most vulnerable part of any padlock—the shackle.