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Locksmithing/HHM safe combo change


I wanted to change the combination on an old Herring Hall Marvin floor safe.  Took the dial box apart and saw that the  number plate dials were reset with a 1/8 inch square inserted in all plates at once.  I could not figure out which position the number dials should be in to unlock.  After fooling around for two and half hours, I noticed the cover plate for the dial plate box had a square hole in one corner.  Rounding my square bar stock at the correct position I was able to lock and unlock the 3 number plates by inserting the home made tool thru the box hole and the three plates all at once.  The problem is my new numbers are off by one to open the safe.

i.e. 25-50-25 needs to be dialed 26-49-26.

This means that my number plates are off one number in the clockwise direction as viewed from the front of the safe.

How do I insert the square bar without opening the number plate box and why am I off one number ??

Thanx in advance for your time on this.


PS, the bar stock cost $1.18 with tax, I wonder how much the real HHM reset key cost.


First off, I NEVER recommend DIY projects like this for the same reason that I don't recommend using locksmiths for safe work.   Not having the correct tools, knowledge and/or training, can result in an expensive lock out.

There are a number of reasons that your combination is off, but knowing this is not going to help you, and training would take the better part of a week in lock operations.

You basically have three options at this point,
1.   I recommend that you have a safe technician from a local safe company, service the lock to make sure there are no problems, and to set the lock correctly.
2.   If you elect to make this a DIY project, you can either:
    A.  Live with the combination that you've set, or
    b.  make the necessary adjustments to the combination to obtain the combination that you want.   IE - (-1, +1, -1),    If you set your combination at 24 (-1) - 51 (+1) - 24 (-1), it should dial up as 25-50-25, if your measurements are correct.

NOTE:  DO NOT close and/or lock the safe door until after you have tested your new combination successfully several times.

As far as the correct changing tool, I would need to know what lock you actually have.   HHM was not and did not make locks, they were a safe manufacturer.

Hope this helps.


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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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