[substeps] Most padlocks are single-lock shackles. A single-lock shackle is secured shut on one side, whereas a double-lock shackle is secured shut on both sides.
[header] How to break a lock [title] Determine whether your padlock has a single-or double-lock shackle. [step] In most cases, this will be impossible to determine by just looking at the padlock. Check its packaging, contact its manufacturers, or research it online to discover what kind of shackle it has.