Master Lock 1-9/16" (40mm) Wide Laminated Steel Pin Tumbler Padlock with 3/4" (19 mm) Shackle

The opening you need to clear is set by the shackle: 3/4 inch of clearance under the crossbar, 5/8 inch between the legs, and 9/32 inch shackle diameter. So the hasp staple or chain link has to accept a 9/32 inch rod, and the thing you are locking through can be no taller than 3/4 inch. That short shackle is the standard No. 3 height, good for tight hasps but not for looping around a post or thick gate bracket.

Yes. The 3 Series is sold keyed alike (KA) so one key runs every lock in the group, or keyed different (KD) so each lock has its own key. Keyed alike is the usual choice for a property manager who wants one key for all the gates, meters and storage units on a site. If you already have No. 3 locks in service, you can request a specific key code so new locks match the key your crew is carrying.

No. The 3 Series uses a non-rekeyable 4-pin W1 cylinder, so it cannot be pinned into a facility master key system or rekeyed by a locksmith. If you need padlocks that fall under a building master, you need a padlock built to take an interchangeable core or a rekeyable cylinder instead. What the No. 3 does give you is keyed alike groups by key code, which covers most fleet situations short of true masterkeying.

The body is 1-9/16 inch wide laminated steel with dual ball bearing locking for pry resistance and a hardened steel shackle for cut resistance. It is catalogued as residential grade, so treat it as a general purpose lock for storage, lockers, hasps and low risk gates rather than a high security application. For a job site trailer, an exposed yard gate or anything an angle grinder or bolt cutter is a realistic threat to, step up to a shrouded or boron shackle padlock.

Pin count is how many tumbler stacks the key has to line up. The 3 Series runs a 4-pin W1 cylinder, which gives fewer possible key combinations and less pick resistance than a 5-pin or 6-pin cylinder, but is the common configuration for general purpose padlocks. Where you are keying a large property and want more unique combinations across the site, or you have a real picking concern, specify a padlock with a higher pin count.

It ships carded for showroom or peg display, which suits a distributor or hardware retailer putting it on a rack. If you are buying a quantity for a maintenance shop, that carding is packaging you will throw away, but it does not change the lock.