impressioning

[dmux]

anyone here really into impressioning? i wondered how does master key (SFIC) impressioning work? if anyone has ever done it and made a master key, since master keys are a higher bidding than change keys, would it be easy to create the master key?

just wondered, impressioning just interests me, making a key out of a blank.. amazing..

[ridinplugspinnaz]

anyone here really into impressioning? i wondered how does master key (SFIC) impressioning work? if anyone has ever done it and made a master key, since master keys are a higher bidding than change keys, would it be easy to create the master key?

just wondered, impressioning just interests me, making a key out of a blank.. amazing..

While it's true that in schemes like TPP mastering the master key usually has at least a couple pin stacks with a higher (i.e. more shallow-cut) bitting, most competent master-keyed systems will also make the master shear line on a couple pin stacks lower than the change key bitting. The reason for that is precisely so that the master bitting can't be determined simply by examining one core in the system. If the master bitting was just the higher shearline for each pin stack, the TMK bitting would be trivial to recover from even a single lock. When you mix up the master bittings though, that leaves a would-be attacker with a search space of 2^n possible keys for a TPP masterkey system, where n is the number of pin stacks in the lock.

[raimundo]

That seems like two questions, one of them is answered in Matt Blaze paper on "rights amplification" so refer to that for the masterkey part of the question, its all there.

Impressioning Is a must do for understanding locks and locksmithing, after you have done impressioning, you will always recognize a key cut to high, as it will have the impressions in it.

I use a common 8 inch flat file to put an acute knife edge on the blank. Others just prepare the top edge of the blank with some fine filing. I'm from the knife edge school.

I use a ten inch (my favorite 12 inch is gone now) fourth cut rattail file. The fourth cut is relatively fine, but still impressions fast. the thin point centers it on the impression, and the full length of the file cutting through that first mark widens and deepens the cut.

Others use the expensive pippin file, which has only one rounded edge. If I were designing a file just for impressioning, it would be a triangle file with three rounded edges, so that any damage, rust or filling up will not

Don't talk about impressioning with needle files, thats just handicaping yourself, use a full 8 or 10 inch file at least, the pippin file offers nothing that can't be gotten from the rattail file and a triangle file if you must use a flat edge to get the MACS slopes.

Always approach an impressioning job with a number of keyblanks ready to go, You may think that your such a never miss impressioner that you always get it on the first blank, but every lock is different, and its easy to look super competent if the cuts are all high and you opened it in two minutes. But realisticly, if youre going to impression keys, do not allow a broken have finished impression to halt progesss.

I believe that impressioning should be done with the smallest petersen nebraska vicegrips you can buy, I used the 6 inch until the 4 inch ones came out. I believe that it its too easy to damage the blanks with a larger heavier plier.

I file a groove in the back of the bow of the key, then I set the vise grip on the bow very hard with the wirecutter in the jaw fitted to that slot in the bow, to eliminate most smearing around of the key bow in the jaws of the vise grip. Ive never used one of those handle things, I tend to think its unnecessary and probably slows the process to fit this on the blank tightly.

[Sven]

i would defer to mr hank spicer (rip) and any of his videos. although i would consider myself proficient with my impressioning abilities, i generally exhaust alternate solutions before deciding its time for a knife edge. i have access to origination equipment, so i feel, in most instances, my customer deserves a code cut key (even if this means decoding a successfully impressioned operational key) i never give a customer a worked key- worst case i copy my work key. about the only exception would be post/ barrel type keys, as i generally file those to fit.

i would like to emphasize that knowledge of the lock helps me impression. i use a thin 6 inch bastard cut flat file and an 8 inch 4 cut rat tail file. any small pair of locking pliers work as a holder for me. i file on my knee, using a shop rag to save my pants. i also break the tips off my rat tails for this reason. if, for whatever reason, my key comes back wet, i find any electronics/ contact cleaner with a straw helps.

best wishes.

[Sven]

dog cut? really? thats kinda weird forum software... the technical term is bas*ard cut. anyways... one last thing, i like to clamp my blank as close to the lock surface as possible- i insert the blank and then clamp to avoid the blank being not fully seated. i generally also pick the lock prior to starting- to avoid the embarrassment of "here is a key to a lock that does nothing." anyways, it always helps to know how many cuts to look for.

best wishes.

[raimundo]

Dog is apparently what the filters replace the bastardcut spec with. The poster did not write it that way, if you see things like roadapples, that means horseshit. and donkey is .ass

[bumpin88]

That is some good tips for impressioning. Sure answers some of my questions? Though I did have one about what types of locks that can be impressioned, and if there was any type of lock that can not be impressioned?

[datagram]

That is some good tips for impressioning. Sure answers some of my questions? Though I did have one about what types of locks that can be impressioned, and if there was any type of lock that can not be impressioned?

Combination or electronic.

dg

[5thcorps]

what's the best file to use for impressioning?

[ToolyMcgee]

what's the best file to use for impressioning?

I've heard #2 swiss cut pippin file, or a #4 swiss cut pippin file for faster material removal. Personally I can't afford any swiss or jewelers files, so I use a decent diamond file. It really helps to prepare the blade with a bastard file to make a knife edge, but don't bring it to a point or you won't see the circlet as easily, if at all. It's seems with impressioning that the harder the lock is to pick, the easier it is to impression. So the high cuts with security drivers are a breeze as you are reverse picking the lock with a key blank and don't really encounter the security features. Whatever file you choose make sure it leaves a dull finish on the blank. The pin polishing the dull surface is what leaves the mark. Don't use anything but brass blanks unless you want to waste the rest of your life impressioning a single key. It really takes 4x as long with a harder blank.
Master Lock #532

The impressioned key next to the duplicated key the locksmith cut
This was my first real blind impressioning victory with security drivers. 1 hour 33mins. Tool making was an immeasureable help to the process. Not quite the rush picking gives, but every bit as exciting and every time I open the lock with the key it's like a good pick. There is nothing so ludicrous as using a blank to pick a lock. It's black magic smooth when you do it in less than 15 mins.

-Tooly

[Raymond]

Congrats Tooly,

Only one word of caution - keep the deep cuts open with shallow ramps so the key does not get stuck. This also keeps the key from marking while moving it in and out.

[ToolyMcgee]

Congrats Tooly,

Only one word of caution - keep the deep cuts open with shallow ramps so the key does not get stuck. This also keeps the key from marking while moving it in and out.

Thanks

Yeah, I was playing with fire on that cut simply because I only had one file to work with. No flat sided files. If it would have been deeper in the lock it probably would have been snagged at some point. I was noticing that the marks the pins were leaving at the top of the slopes were similar to the impressioning marks, and without magnification it could be a real problem, especially early on. I pretty much stink at cutting keys. It's something I've gotta work on. Alot. Thanks for the good advice.

-Tooly

[ToolyMcgee]

#2 swiss cut pippin file, or a #4 swiss cut pippin file for faster material removal.

Scratch that. Reverse it.

-Tooly

[Raymond]

You can make a triangular file into a great ramp file by dulling one corner. Use a grinder or a belt sander and smooth it off so it cannot cut down at all. It must cut only on both adjacent flats. Then put this dull edge in the bottom of your key cut, and lay it over to cut the angle you want. This also makes most keys go in and out of the lock much more smoothly. It is the same as using a code cutter set on 'laser cut.'

[ToolyMcgee]

You can make a triangular file into a great ramp file by dulling one corner.

It's really handy when you answer questions I havn't even asked yet. I've just been awkwardly fumbling around with my files when it should have been so obvious to modify them into what I need instead of wasting time fighting with them. Thanks Raymond.

So, I've done a couple padlocks and now I'm to one where it's really slow going. The keyway is really tight to the blank SC4 and I was thinking of removing material to give it more wiggle room. Already took a some off the bottom of the shoulder, I talking about the reducing the size of the blank where it's in the warding. Does anyone have a tried and true method for doing that, or am I overthinking it.

-Tooly