impressioning knife edge

[toomush2drink]

Just a thought but is there anyway to adjust the temper of a key blank to make it easy to impression with ie softer ? I have read a lot on here about making metals harder for picks etc so it has provoked these thoughts.

[Romstar]

Brass is an interesting metal. Unlike iron, or steel it tends to be soft in it's normal cast state. Common brass in use today tends to be an alloy of 70% copper and 30% zinc. The zinc increases the strength and also increases the ductibility or the ability to form the metal.

Hardening brass is normally acheived through a process called "work hardening" whereby the more you beat it, the stiffer and harder it gets. This is caused by a compaction of the molecular structure of the material itself. Heating the metal causes it to return to it's relaxed or uncompacted state, and can actually deform a part.

This applies to key blanks because most blanks are not cast, but rather stamped, from brass stock, and therefore have been compacted at the time of their manufacture. This increases their strength, but makes it impractical to rework the metal.

Brass also has the interesting characteristic of dissapating heat in a relatively quick fashion, unless you focus the heat. Unlike lead, which has a melting point of 621 degrees F., brass has a melting point between 1650 and 1750 degrees depending on the alloy of the brass. The most commonly used brass for key blanks is known as "cartridge brass", and this has the highest melting point.

So, after I have said all of this has it really answered the question? Well, sort of but in all honesty, the simple answer is this:

Heating the brass won't make it softer for impressioning purposes. You may get some soot on the key though, and that can help sometimes. A lot of locksmiths completely avoid this old technique, and trust in a good light, and a magnifying glass.

Keep on practicing.
Romstar

[Cameron Flint]

I'd also like to add a question to this..., and yes, I've looked and searched the major guides available here; maybe I missed it...
This will be a 3-part quiz.

Firstly, I use the "el-cheapo" 5-piece hobby set I found at Lowes or somewhere (I'm really a miser and my buget's low) and found that after filing for awhile with the round or tapered files, that pin marks would often appear barely visable; but towards the sides of the U. So I wouldn't know whether to level the U, or go deeper...

In addition, whenever I would Soften the U to a V, the file would leave slight scoring marks on the bottom of the cut, making it extremely difficult to tell those and the genuine marks apart.

Thirdly, can anyone suggest a home-made file guide? Usually I block it's path with a pair of vise-grips or pliers, but it's kinda tedious.

Could anybody lend some tips? It would be greatly appreciated.

[Romstar]

Cameron,

You're going to hate me for these answers, but here they are.

1. With the exception of Medeco Bi-Axial locks (might be another one or two) where the impression appears is the CENTER of the cut.

2. To solve your file mark problem, pull the file backwards once or twice. This won't cut the key, but will smooth out your file marks. Polishing them in effect.

3. This is the one you're really going to hate. For your file guide...... use your thumb.
Begin all of your cuts very slowly, and deliberately. This will get the best cut from your file, and cause it to be much straighter. As you continue down in the cut, use your thumb again to stop the file from going too far.

Also, become familiar with the depths and spaces of as many locks as you can, or at least the lock you are impressioning at that moment. With time and practice, you will be able to tell the difference between a .010 and .015 cut. Even though that seems like a small measurement, just remember that everything is relative.

Good luck,
Romstar

[Cameron Flint]

Yo man,
I don't hate you... I'm not too proud to learn! Besides, no pain, no gain, right???
I appreciate your help much, will try asap.
-Cam

[Romstar]

Yo man,
I don't hate you... I'm not too proud to learn! Besides, no pain, no gain, right???
I appreciate your help much, will try asap.
-Cam

Hell yeah, I love that attitude.

Let me know how you do. If you have any more problems, I will try to help you out.

Romstar

[Cameron Flint]

Talk about attitude...
YES! It finally did work, and I'm thrilled. I bought a dial caliper and 4 key blanks, 16 manuals (Phillips) and went to town. Your tips really helped, thanks, I think that generally speaking, what confuses beginners is WHAT TO LOOK FOR. It helps to know where, what, and all that good stuff...
Anyway, I'm working on a master lock and am learning the importance of giving the pin enough space...
I did a normal key-in-knob lock, and found it easier mainly because of the leg room at the bottom of the cut, also I think the smaller locks are more presise (I could very well be wrong) even though there were 5 pins instead of 4.
I'm off now to figure out licensing and all that stuff, hopefully I'll bring up some dirt...

[Cameron Flint]

I haven't had too much trouble seeing the marks nowadays... however, I
do seem to be braking some blanks lately...

I've tryed the marker, and it works somewhat, but somehow I don't like it.
This could be because I have only tryed it with a black one...
Before I begin I put a knife edge on the blade , and use the marker to mark the easily visable marks low down for future reference, because it's harder to put an edge on after you start cutting.

[raimundo]

1. Mr B imagines that when the key is turned to bind the pins, all five bind equally, sometimes yes, particularily at the start when the blank is uncut, but later, because of tolerances in the fit of the key in the keyway, the fit of the plug in the cylinder, and the fit of the pins in their collums you may find that one pin will take all the pressure, and therefore releave the pressure on other pins. Do not file on tiny marks, file the really apparent marks, the unmistakable ones.
2. I knew a guy who annealed some keyblanks once, Jack llewylln of cernys locksmith sanfranciso, put some blanks in his self cleaning oven for the hot cycle, they got so soft they were useless for impressioning because they would tear off when binding the pins.
3. Envision a key blank in a keyway that is loose enough that there will be no problem putting the key in and pulling it out, do you think that it will align straight all the way to the back when turning? or will most of the pressure be transmitted near the open end of the keyway?
4. bind clockwise, bump up, bind clockwise bump down, bind anticlockwise bump up, bind anticlockwise bump down repeat, repeat, remove and read the marks. File strongly and straight accross on the heavy marks, file lightly on nearly good enough marks, and leave the tiny marks alone until later in the process, this pin starts to bind more heavily when the pin taking all the pressure in the early part of the process has reached shear and no longer takes pressure.

[MrB]

Thanks for the feedback, raimundo. I did suggest to file only one mark at a time, and naturally that would be the most apparent mark. Now an expert could file more than one mark at a time as you describe, but perhaps a beginner should take it slow and not get so ambitious?

Or would the gentle filing of the less evident marks provide a clean fresh surface to pick up new marks and avoid confusion with old marks?

[Varjeal]

If you're using an extremely fine cut file such as the swiss #4 or so, you can get away sometimes with a light brush of the file just to clean up the surface. This can be problematic though, if distance between depths is nominal and your previous work has already put the depth at the edge of tolerance. Hope that makes sense.

[HeadHunterCEO]

When i teach people to impression it is exclusivly on a 1200 at first
the reason is that it is harder to screw up the spacing and depths
this is important for manufactures such as nissan or mazda where the spacing is very tight


if you have one depths with the code series then cut them on a machine first

if you have "no cuts" like on an sc1 then just barely graze the blank with the cutter. if yu do this right it will remove almost no brass from the key but will indicate the correct spacing . when you get the spacing rub the finish off across the blade with a real fine file such as a pipin

this will tell you exactly where the pins or wafers will leave marks.

every time you wiggle and it marks cut it to the next depth.
i reccomend one cut at a time even if 2 are marking deep

you can make 2-3 cuts in a key at a time when you get better

do not cut "ghost marks"
if a mark is faint then reinsert and wiggle again

pin locks will leave dots onthe blade in the middle or real close depending on how worn the lock is.

I do not reccommend knife eding pin locks for this reason.

knife edging wafer locks is alright but be careful not to snap the weak blank off in the door.

you don't have knife edge wafer locks.
they will leave dents in the left or right edge of the blade that can be seen rather easily with practice

any chrysler between 86-89
any ford ten cut trunk lock or door lock

make great places to start learning

[raimundo]

Of course if I had a 1200 I would use it, or even a clipper, but the discussion seemed to be about impressioning with a file.

[ufd538]

I do not blade with pin tumblers, but do blade on wafers.

blading with wafers make it extremely easy to see, I can usually make a key in the same time if not faster than picking it. Another good reason, is that some wafers can be bent easily, blading the blank...therefore weakening the blank, will make it harder to break/bend wafers. You would more than likely break the key before you mess a wafer up.

I blade on both sides, and blade the cuts as I go.....I never file the cuts flat, but just blade the deeper.

Much care should be taken with blading though if you do not get a straight, fine blade, it is more or less a waste. Also, you should be very careful in maintaining the original heighth of the key. Once you blade enough, blading it right become quicker and easier.

for pin tumblers, I just lightly file the top, so you have a nice flawless surface, just as everyone else mentioned.

the more you impression, the easier. and as previously stated, if you're not sure a mark is a mark, don't file, that is unless it is the only mark you can get.