Master Lock No 8

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Master Lock No 8

Master Lock No. 8
Master Lock No 8 front - FXE48777.png
Name Master Lock No. 8
Manufacturer Master Lock
Lock Type Padlock, Cylinder
Lock Design Pin-tumbler
# of Components 4
Component Type Pin-tumbler

The No. 8 is a pin-tumbler padlock made by Master Lock. It uses a laminated brass padlock body with an internal key-in-knob-style cylinder. The inner cylinder uses four pin stacks and does not use any security pins.

The No. 8 is a common low security padlock used in the United States. It is one of a line of laminated brass padlocks that includes the Master Lock #2, #4, #6, and #8.

Principles of operation

The No. 8 cylinder is a pin-tumbler lock with four pin stacks and no security pins. The cylinder does not use the M1 key profile but rather a smaller key. The standard No. 8 can be opened in both directions but the "commercial" series body restricts opening to clockwise rotation. The No. 8 is not a key retaining padlock.

Disassembly instructions

The No. 8 cannot be disassembled non-destructively. To disassemble it the rivets that hold the laminated body together must be removed and each layer removed individually. The inner cylinder itself can be disassembled in the same manner as a traditional pin-tumbler lock:

  1. Remove the cam or C-clip.
  2. Insert the key and turn the plug 45-90 degrees.
  3. Withdraw the plug from the cylinder. (A plug follower is recommended)


  1. Remove the chamber casings and take out each pin-stack individually
  2. Remove the cam or C-clip.
  3. Withdraw the plug from the cylinder.


  • The cylinder requires a small diameter plug follower.
  • The plug is retained by a crimp, rather than a C-clip or cam. Above are the generic pin-tumbler disassembly instructions.


The No. 8 is vulnerable to a wide range of attacks. The reduced pin tumbler count and poor manufacturing tolerances makes it an easy lock to pick. It's commonly given to locksport beginners as a "confidence lock"; a lock that is easy to open and inspires you to continue picking. The No. 2 may be vulnerable to one or more of the following:


See also