The Chubb Manifoil MK4 combination lock is used by Government Departments to secure Class A and Class B containers and cabinets. This high-level security lock has four combination numbers. The first three numbers are changeable by the user, while the fourth number is fixed and cannot be changed.
To Open – To open the lock it is dialed as follows:
- Five turns clockwise > (R) to the first number
- Four turns anti-clockwise < (L) to the second number
- Three turns clockwise > (R) to the third number
- Two turns anti-clockwise < (L) to the fourth fixed number (either 0 or 25 or 75 – see below*)
- One turn clockwise > (R) until the dial comes to a stop and the lock opens
* The fourth (last) number will always be either 0 or 25 or 75 – depending on the way the lock is mounted to the safe. Ie: 0 = L/H, 25 = Bolt Down, 75 = Bolt Up
If you accidentally overshoot any numbers while dialing, the whole dialing sequence must be restarted. You cannot turn the dial back to the missed number.
To Lock – Turn the dial five or more turns anti-clockwise < to the left
Changing the Combination
There are four numbers in the combination, but only three are changeable. The fourth (last) number is fixed, and cannot be changed.
Changing the combination is a similar process to the above opening sequence, with the following exceptions:
When changing the combination, the combination is dialed to the alternate second mark at the 11 o’clock position – not the 12 o’clock position that is used for opening
- Make sure the door or drawer is open, and that the lock is locked in the OPEN position
- Dial the existing combination to the 11 o’clock mark (steps 1 to 3 listed above – exclude steps 4 & 5)
- Insert the change key into rear of lock and turn 90 degrees anti-clockwise < (L) until it clicks
- Leave the change key in the lock
- Dial up the new combination to the 11 o’clock position (steps 1 to 3 – exclude steps 4 & 5) Some numbers are forbidden – see note below*
- Turn the change key in the rear of lock 90 degrees clockwise > to relock (click) and remove Test the lock several times with the door open before relocking (Dialling to 12 o’clock)
*Forbidden Combinations for the THIRD number
- When the fourth (last) number is “0” Avoid numbers between 95 and 10 for the third number
- When the fourth (last) number is “25” Avoid numbers between 20 and 35 for the third number
- When the fourth (last) number is “75” Avoid numbers between 70 and 85 for the third number
Common Factory Settings – For First Use
- 40 – 50 – 60 – XX
- 50 – 25 – 50 – XX
XX = Fixed 4th Number
If you would like further information on these high-security locking systems, please contact our Sales Team on 1300 500 600. We have SCEC-endorsed Locksmiths who are experienced working with the Chubb Manifoil MK4 combination lock and the high-security containers, so they will be able to help you.
To see the range of Safes we supply and install go to our Products page.