by MacGyver101 » 24 Oct 2007 13:31
The shackle on cheaper padlocks is normally locked in place by a small, spring-loaded latch. (If you unlock a padlock you'll see a small notch cut out of the end of the shackle: this is where the latch "grabs" onto the shackle and prevents it from opening.) Higher-end padlocks often use latches (or ball-bearings) that only move when the cylinder is unlocked; in lower-end padlocks, however, you can slip a "shim" in along the side of the shackle... this pushes the latch out of the way, and allows the shackle to open.