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Locksmithing/Mosler MRK 302 Sequence


QUESTION: Is this the correct sequence for a Mosler File Cabinet?
Please watch my failed open attempt on youtube



The correct dialing sequence (using the numbers in your video) is:

4 times left to the first number (50)
3 times right to the second number (25)
2 times left to the third number (50)
1 time right UNTIL THE DIAL STOPS (should be around 80).

NOTE:  Left is counter clockwise, Right is clockwise.  DO NOT count the revolutions of the dial, simply count the individual number as it arrives at the 12 o'clock index mark.   For instance you would turn the dial counter clockwise (left), stopping the fourth time the number 50 arrives at the index mark.

I'm not sure what you were doing at the beginning of your video, but turning the dial numerous times before beginning the sequence, is simply wasted effort.   It does nothing for the lock, but if you feel the need to do this don't let me stop you, as long as you realize that you are only doing it for YOUR benefit, and not the locks.

Simply dial the sequence as above - no more, no less.

There are ONLY three reasons that a safe lock won't open, they are:
1.  Incorrect dialing sequence (operator errors),
2.  Incorrect combination (wrong numbers)
3.  mechanical problems.

ASSUMING that the numbers you are using in the video are correct, it appeared that YOU were stopping the dial at zero "0", around 95 and at 90.   DO NOT try to stop the dial, turn it clockwise until IT stops.    If you have dialed the combination correctly, the lever will engage the drive wheel and combination wheels, and when the lock bolt has retracted it WILL NOT be able to turn any further.

If it still doesn't work, you may not have the correct combination.   I would recommend that you have it checked out by a trained safe technician at this point.

Hope this helps,

---------- FOLLOW-UP ----------

QUESTION: Thank you for your help- unfortunately I did not get it open.
I'm not 100% sure but the dial seems to get stuck at random numbers so I'm not sure anyone will get it open even if I have the correct combination.
I'm leaning towards drilling off the fence- I have never done this before but I'm willing to try (and possibly destroying the file cabinet- I paid $60 for it and I'm too cheap to hire a safe technician)
Do you know the location where I should drill?
After reading and researching about safes I have become fascinated with safes and the engineering behind the locks (I'm a mechanical engineer)
Since this is only a file cabinet and I can move the cabinet myself I don't think the door can be that think- do they typically have reinforced steel plates in file cabinets?


If you've read any of my previous answers, you will know that I do not give out ANY opening information other than the correct dialing sequence, for obvious security and liability reasons.
I have no way of knowing what your relationship to the safe is or your authority to even work on the safe.

While I'm sure that you probably are the owner, I'm sure that you can understand these precautions.  These rules would apply, even if you were a licensed locksmith or safe technician, and I knew who you were.  As this is a general forum, and available to anyone to read, I can't put information on the site which might fall into the wrong hands.

As far as the drill resistance of the container, if it is a GSA container or was used by the military (DOD) or any government agencies, then YES, the lock IS protected.

Sorry, I can't be of any further assistance to you.


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Terry V. Andreasen (Andy)


Safe and Vault related Questions; Antique Safe Repair and Restoration; With over 42 years in the Safe & Vault industry, if I can't answer your question I know where to get the answer. Current Project: Restoration of an Ely Norris Cannonball Safe from the early 1900's. Will answer Safe & Vault related questions concerning age, value, restoration, moving, opening & repairing, parts, operation and history. Note: It is not my intention to teach you to open safes or to provide information which may aid in the unlawful opening of a safe. I will not give out drill points or information which I deem inappropriate.


44 years in the Safe & Vault Industry. Owner and Service Manager for one of the largest Safe & Vault companies on the West Coast. Graduate of Lockmasters Safe Lock Servicing, Safe lock Manipulation and Safe Deposit Lock Courses. Graduate of Locksmith Institute. Certified Instructor for the California Locksmith Association teaching Basic and Advanced Lock Servicing, Basic Safe opening and Repairing. Factory Trained by AMSEC, LORD Safes, LeFebure, Mosler, KabaMas, LaGard and Sargent & Greenleaf Author of "The Coffee Table Guide to Antique Safes".

SafeCrackers International and the National Antique Safe Association Safe & Vault Technicians Association (SAVTA)

The Coffee Table Guide to Antique Safes

Graduate of Locksmith Institute 1972 Graduate Lockmasters Safe Lock Servicing 1974 Graduate Lockmasters Safe Lock Manipulation 1975 Graduate Lockmasters Safe Deposit Lock Servicing 1985 Instructor Certified - California Locksmith Association - 1985 Factory trained by AMSEC, MAJOR, STAR, Johnson-Pacific, Kaba-MAS, Allied-Gary, ISM, Lord, Brown Safe, EXL, Mosler, Diebold.

Awards and Honors
2009 - 2015 - Listed in AllExperts Top 50 Experts. All Expert Categories - Safes & Security Containers, Locksmithing, Antique Safes. Retired US Army Chief Warrant Officer (CW4), with 39 years of total service. With numerous awards from Vietnam, Desert Storm and Operation Iraqi Freedom. US Navy - 1971-1981 US Army Reserve 1984-2013 US Army Retired

Past/Present Clients
US Secret Service, FBI, BATF, Local Law enforcment agencies, Diebold, Hamilton Pacific, Red Hawk Int., Chubb International, Bank of America, Wells Fargo Bank, Mechanics Bank, El Dorado Savings Bank, many Credit unions and smaller banks. McDonalds, Togos, BurgerKing, TacoBell, Carls Jr. FoodMaxx, SaveMart, Lucky's, Albertson's, Raley's, Safeway, NobHill, Bell Markets, PW Markets. Great America, Century Theatres, Cinemark Theatres, UA Cinemas, and many homeowners and small businesses. Provide warranty service for lock and safe manufactures. Service Area is Northern California (Fresno to Oregon and Western Nevada)

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