FAQ: The Fine Art of Impressioning (in a nutshell)

[d_goldsmith]

A little, but why would there be no marking once your at the sheer line, the pin would still be stuck against the bottom of the shell?

[globallockytoo]

A little, but why would there be no marking once your at the sheer line, the pin would still be stuck against the bottom of the shell?

Explaining it without demonstrating it is more difficult.

If the location you impression suddenly starts showing stronger marks it usually means two things. 1. You are bang on the correct depth. 2. You are too deep.

When the location stops marking it usually indicates that you will be very close.

There is no magic to it at all. Simply that after successfully impressioning your first pin tumbler lock, you will have a much better understanding of the whole pin tumbler principle and about picking as well.

[freakparade3]

Because of this thread I just made my best hand filed key to date. Thanks guys. I learned more about impressioning from this than I did from my Foley-Belsaw book.

[d_goldsmith]

What I meant was, there has to be more force between the key and the pin to create a more distinguished mark, why is there more force? And why does this force stop when you are at the sheer line?

[Romstar]

The marks vary, and/or stop because of the way the driver pin acts on the key pin. Once you have lowered the driver to the shear line, the type of pressure it exerts is different. It hangs on the shear and doesn't press against the key pin in the same way.

Realize that you are starting with a full blade key blank and stuffing the pin stacks up into the bible. This has the effect of placing both direct and shear (sideways) pressure against the key pin. Since key pins are rounded or pointed, this pressure creates a deeper and often wider mark.

Once you have lowered the stack to the hear line, there is no more shear pressure and the marks become very minute. Since it is difficult to see them in the first place this lessening of the mark has the effect of making it seem to disappear.

Also, since the key should be filed to the correct depth, there is less direct pressure on the key pin as the driver is sitting on the shear line. This reduces the direct pressure, which again causes the marks to decrease to the point of non existance.

Going past the proper depth will result in more marking, so you have to pay careful attention to the marks. It really does help if you are fimilar with the depths of the particular lock you are working on. This will assist you in filing to the proper location, and not going too deep.

I hope this helps some.

Romstar

[d_goldsmith]

It does. Thank you. I now understand why the mark disappears. I still don't understand exactly how the key pin causes the mark though. That might sound stupid so I'll clarify that I know the key pin is in contact with the blank. I'll re-read all the explanations of the method.

[globallockytoo]

It does. Thank you. I now understand why the mark disappears. I still don't understand exactly how the key pin causes the mark though. That might sound stupid so I'll clarify that I know the key pin is in contact with the blank. I'll re-read all the explanations of the method.

As you turn the keyblank in the keyhole, it causes the pins to bind in the cylinder. As you lift or pull pressure on the key, the pins (which are binding), need to travel somewhere, so naturally they will head in the direction of the softest point, in this case the keyblank. This pressure causes indentations (or marks, spots) to appear on the blade of the keyblank?

Does this help?

[Romstar]

Impressioning is the next best thing to a black art. There are some excellent teachers of the technique out there, but I would be willing to bet that many of them would be hard pressed to explain exactly how it works.

If you can find a copy of Hank Spicer's, "Impressioning with Hankman", you will be doing great. Its an excellent book and does an amazing job of teaching this skill.

Romstar

[d_goldsmith]

Thanks guys.

[parapilot]

If impressioning a master keyed lock would you impression the master first for the rest?? Would that be the first sheer line you would come across? Just wondering.

[Romstar]

In most cases you get something random. A mix of the change key and the master, or sub-master.

There is no way to tell the difference between the marks being made, so whichever makes the best marks is what you get.

In most cases you aren't going to be impressioning a master key and if you are its only going to be to get someone in where they need to be. I wouldn't turn over an impressioned key to a masterkey system to be honest.

Come to think of it, in cases of master key systems you are either the lockie that made the system, and as such don't NEED to be impressioning because you have the codes written down, or; you are opening a door to retrieve somebody's keys. In which case, they will have the proper key on their ring. If in some rare circumstance you inherit a building with masterkeyed locks and you do NOT have the system paperwork you should honestly just start over. Its better in the long run, the customer has a new system, and you can service them much easier by knowing the system that you laid out.

Other than that, you just get what you get.
Romstar

[Wrenchman]

I had been trying and trying but with no luck, not being able to see anything I would just file anywhere and in the wrong places, broke 10 keys!

When I stumbled over these words:

It's another one of those deals where patience and determination (and sometimes a lot of keyblanks) really pays off.

These where the words I needed, after I read this, I went down in my office and made a perfect key the first time, then I made a copy, and in the same hour the customer arrived, needless to say I was happy and I felt great, and I still feel like I am flying(now two days after)

Thanks

Ps. It was a wafer and I used a triangle file!



Wrenchman

[Mutzy]

The other day, I had my first go at impressioning a pin-tumbler lock (others before it have been tilt-a-door handles with discs), this one was a Lockwood 245 padlock with 5 pins. The method I was taught for getting the spacing was to knife-edge one side (If turning clockwise, file the left side of the blank, right side for CCW turning) and turn the key.
Using a small hammer, tap the head of the key down a few times and then tap the head up a few times. This should get you a few good marks, and is a good process I found for cutting the shallow cuts.
When you get down to the deeper cuts, the method I was taught was to turn the key and pull the blank in and out a few millimetres, and file the cut that has the most definite mark.
The file that I was using was an actual impression file, which is similar to a rat's tail file, but smaller and more fine.

The boss was sceptical of my success (hey, i would be too, if I saw an apprentice trying to impression a padlock, without prior practice... ) but was quite surprised when he came back into the workshop later to see me unlocking and relocking the thing. Go me.
In the end, I decoded the key and cut it to code to test it. Everything worked smoothly. Next task is to take a few of the key-less padlocks home and try to make keys for them. And to set aside a weekend to do it...

[Varjeal]

Something like providing tension to open a lock, the turning motion used when impressioning must be firm enough to provide marks without damaging the key.

This is sometimes difficult to avoid if the key has several deep cuts or a lot of turning pressure is used. Regardless, if you note that the key has cracked or twisted significantly, stop and duplicate onto a fresh blank before proceeding. It's really not worth having the key bust off in the lock.

[raimundo]

I read all six pages and didn't see a reference to breaking off the blank until the last page. Always approach an impressioning job with a number of appropriate key blanks and do not expect to always get it on the first blank. Yes, I can usually get a key with one blank, but it is still foolish to only come with one blank and keep watching that shoulder area where the fractures start several bumps before it becomes two pieces, most experienced impressioners are watching this area for signs of weakening, if you are confident that you have not filed any false impressions, yes, copying the work before restarting is the way to go, but if you are new to impressioning, put the first try behind you and start over at the beginning, later you can compare the results to see if it went the same way both times. because the keyway meanders accross the pin drilling, you can often find that the impressions are coming in at the edge of the blank, do not jump on such an impression right away, it will deepen and become more distinct through some additionall bumping, when you see a ding with reall spalling at the edges, (metal pushed up from the crater) thats an unmistakeable impression. if you break the key off, or quit because its fracturing, do not let that get you down, prepare another blank and keep going until you have a key. it is not failure to break a keyblank, its just a temporary difficulty that you have to ride right over.