High Security Safe Keylock Retrofit

We recently sold a used high security safe. Every used safe we sell goes through a thorough servicing and inspection to identify any worn parts or items needing service. Worn parts are then replaced. What makes our company unique is our ability to remake many parts that become worn in a safe. In doing so, we can offer our customers a used safe that has been rebuilt and will last for years to come.Most of our competitors do not have this ability as this ability requires knowledge and equipment from the machining trade.

Some of them do not even service and inspect their used safes before they are sold. If they do inspect the safes and identify something in need of service, many times the repair that is done is very poor quality, resulting in the safe needing service (sometimes frequently) shortly after the safe has been sold. Unfortunately, in this situation, the safe almost never receives the proper service and the problem then becomes a chronic problem for the remaining life of the safe. The subject of this post is the proper replacement of a worn key lock from a 30 year old high security safe.

Modern quality safe locks whether electronic, mechanical or key lock; conform to standardized dimensions (AKA ‘standard footprint’) adopted by the industry. Years ago, many manufacturers did not use standard footprint locks in their safes. The key lock in the safe we sold was not a standard footprint. What follows is a walk-through of everything I needed to do to allow the safe to accept the new lock (standard footprint).

Photo 1 shows the old key lock as I was unscrewing it from the door. The arrows indicate points of interest. The four left pointing arrows are directed at the mounting hole locations in the lock case. Take
note, that the mounting holes are located outside of the lock body. The other two arrows point at the lock bolt and lockbolt extension. In this safe, as in many others, the bolt that sticks out of the key lock does not block (lock) anything directly. Rather, it is connected to an extension which performs the blocking several (sometimes more) inches away from the key lock itself.


Photo 2 (which we will get back to later on in the post) shows the modern standard footprint key lock that was installed with the new extension I made.Take note the mounting holes on this lock are located inside the lock case and the size and shape of the lockbolt are different.


Because the dimensions of the safe locks and their lock bolts were different sizes, this required making (machining) a new lockbolt extension to fit to the new key lock to be installed. Photo 3 was taken while I was working on making the key lock extension in the lathe. The key lock extension starts out as a round piece of steel.


Photo 4 shows the piece of steel still in the lathe, after some progress had been made.

Photo 5 shows the completed new key lock extension at the top of the photo and the old key lock extension under it.

Photo 6 brings us back to the lathe where I have cut a 3/16” thick slice of a piece of 1 ¼” diameter steel.

What is that for you ask? Photo 7 gives the answer. Photo 7 is a picture of the mounting plate the key lock sits on with the round piece of steel.

Notice the arrow in photo 8 is pointing to the piece of steel I had cut (shown in photo 6) which now sits quite nicely in a hole in the mounting plate.

The reason for doing this is due to the key locks having different dimensions. If you take a look at photo 1 again, you’ll notice the old safe key lock sits on the mounting plate and the large hole is located directly above the
lock bolt.

The new key lock has one of its mounting screw holes located directly on top of the large holes center. This required me to fill the hole so I would have steel to screw the lock case to. You may be asking what the purpose of the large hole is in the mounting plate. In this particular safe it is pointless,though the safe manufacturer did use that same mounting plate in various orientations in their different model/size safes. So it did serve a purpose in some of their other model safes.

Photo 9 shows the completed retrofit -the new key lock with the new lockbolt extension installed on the mounting plate in the safe. Note the arrow is pointing to the piece of steel (that filled the hole) that is now welded in place. As you can see, one of the mounting screw holes of the key lock lands on top of the newly welded in place steel.


Another retrofit job done right!