Chubb Manifoil MK4 Combination Lock

Chubb manifoil MK4 combination lock

The Chubb Mark IV Manifoil combination dial safe lock has been installed on many Government containers and cabinets, It is a combination dial lock that has been the Australian Governments security standard for many years.

The Manifoil MK4 is a high level security combination dial lock, its lock sophisticated moving parts in the lock mechanism such as a pair of lead shields to prevent X-ray examination. The MK4 lock has the same appearance as a standard combination lock, but the four number combination is always dialed in the same way, five times clock wise to the first number, four anti-clock wise to the second, three clockwise to the third, two anti-clockwise to the fourth then turn clockwise about half a turn until it opens.

Even though there are four numbers in the combination, only three are relevant and settable. The fourth is fixed and will always be 0 for a right-swinging lock or 25 for a top-swinging lock.

You will require a key when securing a combination on an Manifoil mk4 lock. This change key is unique to a Manifoil MK4 and it is inserted through the small covered flop on the back of the lock cover.

A guide is set to follow when changing a Chubb Manifoil MK4 combination lock.

The Chubb Manifoil Dial lock has (4) combination numbers and the first (3) numbers are re-settable by the user whilst the (4) number is fixed and cannot be changed.


To open a Chubb manifoil MK4 lock , dial the lock as follows to open.

A. 5 turns clockwise (right) to the 1st number
B. 4 turns anti-clockwise (left) to the 2nd number
C. 3 turns clockwise (right) to the 3rd number
D. 2 turns anti-clockwise (left) to the 4th number (either 0 or 25 or 75: – see below*)
E. 1 turn clockwise (right) until the dial comes to a stop and the lock open.

*Please note: the 4th (last) number will always be either 0 or 25 or 75. This will depend on the way the Manifoil lock is installed on the safe. Example: 0=L/H 25, 25= bolt down, 75= bolt up.

If whilst dialing numbers you accidentally go past numbers you need to start the entire sequence again. You cannot turn the dial back to the missed number.

To lock a Chubb Manifoil MK4 lock

Rotate the dial (5) times or more anti-clockwise (left).

Changing the combination on a Chubb manifoil MK4 lock

There are (4) numbers in the combination, but only (3) are resettable. The (4) last number is fixed and cannot be changed.

Changing the combination is a similar process to the above opening procedure but with the following exceptions.

when changing the combination the combination is dialled to the alternate second mark at the 11 o’clock position that is used for opening.

A. Always make sure the door is open and the lock is locked in the “OPEN” position.
B. Dial up the existing combination to the 11 o’clock mark (steps A to C and exclude steps D & E)
C. Insert the change key into the rear of the lock and turn 90 degrees anti-clockwise (left) until it clicks
D. Leave the change key in the lock
E. Dial up the new combination to the 11 o’clock position (steps A to C and exclude steps D & E), some numbers are forbidden – see notes below
F. Turn the change key in the rear of the lock 90 degrees clock wise to relock (click noise) and remove and test the manifoil lock many times until the door opened before relocking (dialing to 12 o’clock)

Please note, forbidden or no-go combination for the 3rd number: –

  • when the 4th (last) number is “0”, avoid numbers between 95 and 10 for the third number
  • When the 4th (last) number is “25”, avoid numbers between 20 and 35 for the third number
  • When the 4th (last) number is “75”, avoid numbers between 75 and 85 for the third number.

Common set factory code for 1st use:

  • 40-50-60-ZZ
  • 50-25-50-ZZ
    (*ZZ = fixed 4th number)

Choosing A Government SCEC Endorsed Safe

Where a high level security is required, Safeguard Safes are the preferred supplier to the majority of Government & Defense Departments, and Law enforcement agencies for over 35 years and we hold many Government & Defence contracts. SCEC approved equipements are given a classification such as Class A, B, or C. The Chubb Vault Door Holsworthy, Chubb Vault Door Bankers, and the Chubb Vault Door Pacific are all very popular choices that provides high security for your valuable assets.

Contact us today for more information.
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