Mul-T-Lock Junior

The Junior is a dimple lock made by Mul-T-Lock. It is a telescoping dimple design that uses 5 inner and 5 outer pin pairs. The key raises both the inner and outer pins to the shear line. It is marketed by Mul-T-Lock as an "economical solution" in their product line.

Principles of operation
The Mul-T-Lock Junior utilizes dimple keys but functions the same as a standard pin-tumbler lock. The lock uses 5 chambers for telescoping pin-tumbler stacks which contain an inner pin nested within a second, larger one. In addition to it's telescoping pins, the Mul-T-Lock Jr. utilizes a variety of security pins to deter picking. Driver pins are a mix of standard and spool designs. Outer key pins are both standard and torpedo pins. To open the lock, all 10 pin-tumblers must be aligned at the shear line. (See also Pin-tumbler, Principles of Operation)

Mul-T-Lock keys are noticeably different from pin-tumbler keys due to the mechanism of the lock. Each pin position has a pair of concentric cuts to match the inner and outer key pin lengths. The Junior uses the 008J keyway, the key is bitted on the sides and edges of the blade and is reversible. The dimple key of the Junior has five cut depths for outer pins and six, different cut depths for inner pins.

Disassembly instructions
The Mul-T-Lock Junior is disassembled in the same way as a traditional pin-tumbler cylinder. Steps vary slightly across different cylinder form-factors.


 * 1) Remove the rear plate (RIMO cylinder) or unscrew the retaining cap (KIK cylinder)
 * 2) Insert the key and turn the plug 30-45 degrees.
 * 3) Withdraw the plug from the cylinder. (A plug follower and core shims are strongly recommended)
 * 4) Care should be taken to keep the key pin pairs organized as outer pins of the same size may have different length inner pins.