USN Brass Corbin Cabinet Padlock

[maxxx]

Hi all, hope this works. (last night I tried to post and it gave me an error message DEBUG).

I have an OLD Corbin USN marked, solid brass padlock. Aquired with no key of course. Even the shackle is brass and it is hex shaped. It looks like it has ball bearings for the lower pins. The last patent date is 1909.

I have ten key blanks and have burned 5 1/2 of them so far trying to impression it. My impressioning coach is "Shear Line Jake" and he said to open up the tentative bitting I have made so far, to clear the rather large ball bearings.

On the bottom of the lock, it is stamped 5B56884. Anyone have the space and depth specs, or decode the cuts for a key? Or any tips out there, for impressioning one of these old locks?

This is a loose lock, not attached to anything, and I am the owner of the padlock.

[pelham123]

test reply

[5thcorps]

Can you post a picture?

[Wrenchman]

maxxx
Joined: 16 Sep 2007
Posts: 16777215
Location: NW USA

Look at his post count!

Something sick is wrong with this site!



Wrenchman

[maxxx]

Its solid brass and has ball bearings instead of lower pins.

http://rides.webshots.com/photo/2787800 ... host=rides

[MacGyver101]

Its solid brass and has ball bearings instead of lower pins.

Some very old Corbin locks (this one included, apparently) used balls on the bottom of every pin stack. (Note that they still, however, have both bottom and driver pins, in addition to the ball bearings.) The Corbin Russwin service manual notes:

Code: Select all

You will find a ball bearing at the bottom of pin stacks in some or all chambers of Corbin and Russwin cylinders manufactured from about 1902 until the mid 1960's.  The oldest cylinders have the ball in every chamber.  The number of balls was gradually reduced until only the front two chambers had them. [...]

The reason that "balls on the bottom of every pin stack" were phased out almost 100 years ago is that they posed a significant security problem... bypass techniques aren't an appropriate discussion for this forum, but the technique isn't that hard to figure out if your lock is constructed like this.

[maxxx]

Funny you should mention these facts MacGyver101. I was taking a break from impressioning and got out my picks. Poof..I picked it. The brass on the shackle is nice and shiny where it rests below the body of the lock.

Its dry as a bone inside. I can see the cover for the pin stacks and could pry that off if I wanted to and file a key to fit the stack, but I would rather leave the cover on.

At this point, I am rethinking the impressioning method. I cant see in the keyway very well (where is the cash for a good Otoscope, when I need one) but there *may be* only one ball bearing at the 1st position. Hmmm?

[MacGyver101]

If you have been able to pick the lock, it may be easier now to measure the pin heights from the picked cylinder and use that to help guide your key-making. (It can be difficult with a tightly-warded cylinder, but it is likely to at least get you close...)