What lock do I have?

[luchi]

I purchased a Sargent & Greenleaf 4 number combination lock ($4.00) at an antique store. I removed the back and figured out the combination but have several questions. Hopefully someone can help.
1. My lock has the following info on the back cover: GROUP 2 R (cast) and 6730 (stamped). Does this indicate which lock I have?
2. The lock has 3 large disks and a smaller disk that pulls/pushes the locking shaft. Is this a 3 disk or 4 disk lock( for ordering a change key)?
3. The back case has a hole where a change combination key can be inserted. Can I safely assume the combo is resettable?
4. There is a lever that is depressed when the back cover is in place. The other end of the shaft interacts with a round, spring loaded pin. With the back cover closed the lever keeps the pin retracted, with the cover removed the pin engages the lock shaft and keeps it from retracting. (I read this is called the internal relock?). What's the purpose of this feature?
5.There aren't any holes anywhere on the lock case (besides the change combo hole). What holds it in place when inserted into the door of a safe? To insert the apparatus into a door does it have to be disassembled so the case is inserted from the backside and the dial mated up from the outside? What keep it in place without wiggle or wobble? There is a flat piece of 1/4 steel between the case and dial with a beveled edge on top. Does the bevel interact with a corresponding bevel milled into a safe door?
Based on the number 6730 (serial number?) can anyone guess the approximate age of the lock? I hope to one day weld up a safe and install the lock in the door. I will have to fabricate the mechanism that physically throws the bolts to secure the door shut unless there is a parts supply company.
Any information will be greatly appreciated. Tks.

[cledry]

1. Yes
2. 3 wheel
3. Yes
4. If someone attempts to break in by hammering the spindle in it will lock up the safe lock.
5. The rear cover comes off, you mount the lock using 4 screws with Loctite to the plate on the inside of the door. The dial and spindle are inserted through the door and mated to the drive cam, then the spline key is inserted in the proper orientation depending on the direction the bolt is facing.

http://www.sargentandgreenleaf.com/MC-6730.php

[Squelchtone]

You know, a picture is worth a thousand words. You should just show us a photo of your lock parts...

A video is even better. Here is a video of an expert installing an S&G model 6730 onto a safe door.

This should explain all of the parts and most questions you have.

[billdeserthills]

Are the wheels on your lock brass colored or like the picture above?

[luchi]

My wheels are brass as is the latching mechanism. It appears that everything is brass except the case and the screws attaching the case to the dial. I'm working on some pictures and will post soon. The wheels do not have any numbering on them the like the picture you posted. The deadbolt action is upwards.

[luchi]

Well I have images of my lock and I created an IMGUR account and loaded a few pics. However they went into an album (not individual .jpg). So I deleted the album and reloaded one picture as a Non-album but it still isn't a .jpg extension. This is about to become more trouble than its worth. I've sent a request to IMGUR on how to accomplish such a seemingly simple task but haven't heard back as yet. With Thanksgiving tomorrow it might not happen until next week. Does anyone here have any suggestions (be kind)..

[luchi]

Ok, after my rant I think I've figured it out.

[luchi]

[luchi]

With the lock in its current state I don't think it could be installed into a door of more than a 1/4 inch thickness? Can parts be ordered that would lengthen the internal rod that connects the dial to the wheels? If so, can a rod be inserted into the dial or does a new dial have to be ordered with the rod? I would like to weld up my own vault and use this combination lock. Thoughts?

[billdeserthills]

With the lock in its current state I don't think it could be installed into a door of more than a 1/4 inch thickness? Can parts be ordered that would lengthen the internal rod that connects the dial to the wheels? If so, can a rod be inserted into the dial or does a new dial have to be ordered with the rod? I would like to weld up my own vault and use this combination lock. Thoughts?

You would need to buy a new dial, in order to get a longer spindle In order to avoid also replacing the dial ring, you will need that same style of dial, which is called a 'spy proof' dial.

However, before installing a lock I found and payed a few $ for
I would carefully test it, as there is likely a very good reason why it was removed from the safe it was originally attached to

So much cheaper to simply purchase a brand new lock for your safe, than it will cost to drill that safe open, after installing
a lock that doesn't work correctly

[Tyler J. Thomas]

Bill's right. While the S&G 6730 is a reliable workhorse, your lock has certainly seen better days. If you're going through the effort to build a vault and/or procure a new dial and spindle, why not toss in $60-70 and buy a brand new combination lock for peace of mind?

If I were you, I'd clean the lock up, lubricate it, and mount it onto a wooden display as a learning tool. Tons of information on this forum on how to accomplish all 3 of those tasks. Practice changing combinations, the handing of the lock, etc.

Safe locks are neat to tinker with.....except when you have an Auditcon and a stripped spindle at 6 AM on a Sunday morning and all cash tills for the store are in the safe. Then you start to wonder why on Earth some locksmiths love safes so much.....bunch of sadists.

[luchi]

Thanks for the advice. I like the lock for its heavy weight construction and solid feel and had fun thinking of the possibilities of incorporating it into a safe. However, I most likely will use it as a display/education piece for my grandkids. Maybe incorporate it into a wooden box (with removable bottom) like a treasure chest for them. Thanks again for the input.