Master Lock No 605

The No. 605 is a pin-tumbler padlock made by Master Lock. The No. 605 is a solid body padlock with an inner cylinder that uses four pin stacks and contains security pins. The No. 605 is a mono block padlock with the shackle being a straight piece of metal that slides up and down to lock the padlock. This lock is often used to secure trailer couplers.

Principles of operation

 * See also Pin-tumbler (Principles of Operation)

The No. 605 cylinder is a pin-tumbler lock with four pin stacks and security pins in various chambers. The No. 605 can only be opened by rotating the plug clockwise.

Disassembly instructions
The No. 605 cannot be disassembled non-destructively; to disassemble it the lock must be sawed in half. The lock is nonfunctional once disassembled because the padlock body acts as the cylinder for the lock.

Vulnerabilities
The 605s reduced pin-tumbler count and poor manufacturing tolerances allows it to be easily picked by low skill attackers despite having spool pins. The No. 605 may be vulnerable to one or more of the following:


 * Lockpicking
 * Key bumping
 * Impressioning
 * Bypass
 * Destructive entry