Scandinavian Jail Lock

[GWiens2001]

My latest opening - Scandinavian Jail Lock Key made

Got this Scandinavian Jail Lock without a key.  Was going to pick it, but decided on something a little more ambitious.  Make a key.

Impressioning is kind of out of the question.  This is a disc lock with five iron discs.  There is no sidebar.  When the discs line up, circular cutouts in their outer edges line up with the shackle.

Too late tonight for a full how-to guide, so just the pictures of the lock and key.

First of all, this lock is a bit on the large side.  Certainly would not want this lock dropped on my foot!


The lock and the nearly finished (but operational) key



This lock-on-a-stick is an iron rich food.  



Picture of key turned in lock.  This does not mean much, as a properly made blank will turn in the lock, too.



The key works!!!  The shackle is removed.  By examining the shackle, you can see that there are five discs that engage the shackle.



An end view of the key.  The metal used is 1/4" (8mm) bar aluminum filed to the correct width, center drilled to 3/8" diameter by 2" depth





Key was made by end drilling a hole, then hand filing a blank which would enter and turn in the lock. After that the bits were filed to properly align the discs inside the lock with the shackle.

Enjoy!

Gordon

[femurat]

Wow that's what I call a big key

I wonder if you could pick the lock by applying tension on the shackle and then turning the disks with a L wire or pick.

Cheers

[bembel]

Quite impressive piece of metal and also a nice job doing the key.
Thanks for sharing the pictures.

[Altashot]

Nice one!
I bet you got pretty sore with all that filling.

M.

[GWiens2001]

EDITORIAL CORRECTION: The hole is 3/16"

@Femurat - yes, if you use a right angle pick (like a radiator pick, an normal lock pick or L wire would twist like a pretzel) while holding the lock upside down, one disc will bind before the others. With a lock this old, you may not be able to tell just by tension because of dirt, rust and gunk. Just turn each disc the full rotational distance, about 1/4 turn. If you have the correct disc, when you have turned it the correct distance, you will feel the shackle drop a tiny bit, almost like feeling a pin set through your tension wrench. Then try the other discs until you have opened the lock.

The problem with that method is that some of the discs turn 90 degrees to open, then somehow you have to get to a disc further into the lock through a now tiny hole in the center and still have enough torque to turn the discs. Also, the innermost two or three have that center area nearly fully blocked by the center post, which is why there is a hole in the tip of the key.

An easier method is to use a feeler gauge slid along the inner edge of the shackle until it encounters the first disc. (The discs are counted from the tip of the key. Will explain about that when I do the full write up.). Use that pick to turn the disc until the feeler gauge slides in to the next disc. Think of shimming a pin tumbler cylinder. Just work your way from the innermost to the outermost discs.

@Altashot - No kidding! I have a new notch on my right index finger, too, from trying to keep the file aligned with the right spot. And still, the #2 bitting is thinner than the other 4. The big fat bitting on the key is actually to engage the key rotation stop inside the lock.

[MacGyver101]

I can't quite tell from the photos -- but if the dots are still visible inside the star that surrounds the keyway, you can also decode the cuts from those:

• One dot (⋅) corresponds to no cut (0°)
• Two dots (∶) corresponds to a "full cut" (about 80°)
• Three dots (⋮) corresponds to a "half-cut" (about 60°)

Holding the lock so that the dots are at the bottom, the left-most dot pattern corresponds to the tip of the key -- and the right-most dot pattern corresponds to the cut closest to the bow.

If I'm reading your key right, I think your pattern should be: ⋅ ∶ ⋮ ⋅ ⋮

[GWiens2001]

I can't quite tell from the photos -- but if the dots are still visible inside the star that surrounds the keyway, you can also decode the cuts from those:

• One dot (⋅) corresponds to no cut (0°)
• Two dots (∶) corresponds to a "full cut" (about 80°)
• Three dots (⋮) corresponds to a "half-cut" (about 60°)

Holding the lock so that the dots are at the bottom, the left-most dot pattern corresponds to the tip of the key -- and the right-most dot pattern corresponds to the cut closest to the bow.

If I'm reading your key right, I think your pattern should be: ⋅ ∶ ⋮ ⋅ ⋮

That is correct, MacGyver. Was going to cover that in the write up. I have some copied pages from an article in the Locksmith Ledger that gave that info as well. Won't post pics of the article due to copyright issues, but will cover the information.

The reason they list the angles as about 80° or about 60° is because these were made by lockSMITHS, back when the smiths made the locks and keys. The discs are not perfectly identical, though they are close. So if someone cuts to those exact angles, the lock may or may not work. I am sure that you know that, but some of the newer people may not.

By the way, close on the code. ⋅ ∶ ⋮ ⋅ ∶

Gordon

[mhole]

Gordon - do you mean 3/8" (9mm) barstock, centre drilled to 1/4" (6mm)?

Lovely lump of a lock, and impressive patience filing all that by hand - nicely done!

[GWiens2001]

No, it was late. it was 1/4"x3/4" bar stock, drilled 3/16".

Gordon

[MacGyver101]

Was going to cover that in the write up.

Ah, sorry... didn't mean to steal your thunder there. (In particular after such impressive work on that key!)

I have some copied pages from an article in the Locksmith Ledger that gave that info as well. Won't post pics of the article due to copyright issues, but will cover the information.

Ah, yes: I know the one you mean. I think that article was a reprint from one of the Reed Padlock Code Books.