bump key locAL lockie prob.

[clayton1123]

I recently went to my local lockie and had a 77777 key made. The bum key equivalent of a 99999 key. He made them then took them in the back room and filed down the tips of the key. Out of suspicion I guess. Will these still work or should I throw them out?

[TOWCH]

What part of the tip? What type of lock is it?

[eric343]

If the key is totally flat, then no, it won't work. You need the ramps.

And I thought a bump key had to be slightly deeper than the maximum cut (almost a 10 cut in a 9 cut system), rather than a 7 cut.

[keysman]

999999 refers to the deepest cut... depending on the manufacturer specs, it may actually be a 6 or a 7 ( kwickset).

There seems to be some debate as to weather it needs to be a 9.5 cut to work properly. Personally I have no problem with a "pure 9".
Your mileage may vary.

[jimb]

There seems to be some debate as to weather it needs to be a 9.5 cut to work properly.

I have wondered about this. If you file the tip and the shoulder of the bump key then the pins will be bouncing off the slope of the cut. So why would it need to be deeper?

[clayton1123]

He filed the tips of the keys cuts down so now they are slightly rounded. The cuts may still be high enough to work. Yes it was a kw1 kwiksey key. If anyone can find out if I need to file down to a 7.5, please post it. And yes 7 is the kw1's deepest cut.

[Bump]

Its normal to take about .5 mm off the tip so that it doesnt crash into the back of the lock.

A bump key is a key in which all the cuts are at maximum depth. Bump keys are sometimes called '999' keys because all cuts are at maximum depth. (Dimple locks are 777 keys).

Normally, if you insert a key all the way into the lock, the pins inside the lock touch the deepest point of the cut in the key at the point where the shoulder of the key makes contact with the inner cylinder of the lock. By filing a tiny bit of metal off both the tip and the shoulder of the key, you can create a bump key that can go just a little bit deeper into the lock and is pushed out again a tiny bit by the force of the springs inside the lock, until the pins again rest on the deepest point in the key cuts. Filing off between 0.25 and 0.5 mm works best, it is very easy to take off too much.

Thanks to Barry Wells & Rop Gonggripj.

If you want a full transcipt of their work PM me.

[dsdayl]

You say he filed the tips of your keys. I am confused.

Imagine looking at a key on the horizontal plane.

Starting from the bow there are 5 valleys that the pins will set in ( the low points in this crude depiction of a key)

(|^^^^^

Did he file down the 5 peaks (high points) on the key? Or just the tip? The part that is first inserted into the lock?

If he filed down the 5 peaks. It was just to round those sharp edges off and save wear and tear on the lock. The key should work fine unless he filed them all the way down to where there is nothing left. (which would be a flat key)

Is this what you are talking about? Or am I misunderstanding your question?

[Reserved]

It seems like he just took a little off of the ramps. You would think that would increase the life of the lock so that the ramps don't scratch the pins as bad, and even more so... the key would just slide in easier. If this is the case I would recomend that you take a square file and go a half cut deeper and have the ramps nice and flat.


BTW... the reason why they say a 10-10-10 key is better is b/c if you have a pin that requires a 9 cut depth then when you pump it you are more likely to knock the bottom pin past the sheer line. So, the easy solution is to just go a little bit deeper.


Oh, and by chance... would anyone know where I can just buy a set of the most common keys cut for bumping? (other than a lock smith) I made one Schlade, but I think I took a little too much off of the shoulder... or maybe I am not bumping it hard enough or haven't had enough trys or something.

[eric343]

When making bumpkeys, err on the side of taking off too little. The deformation of the key will cause the key to naturally adjust itself to the ideal. It can't do this if you take away too much material.

Obviously it's best to get it perfect and save the wear on lock and key, but...

[clayton1123]

You say he filed the tips of your keys. I am confused.

Imagine looking at a key on the horizontal plane.

Starting from the bow there are 5 valleys that the pins will set in ( the low points in this crude depiction of a key)

(|^^^^^

Did he file down the 5 peaks (high points) on the key? Or just the tip? The part that is first inserted into the lock?

If he filed down the 5 peaks. It was just to round those sharp edges off and save wear and tear on the lock. The key should work fine unless he filed them all the way down to where there is nothing left. (which would be a flat key)

Is this what you are talking about? Or am I misunderstanding your question?
[/quote]
Yes he took down all 5 peaks but not all the way, only a little off the tops. I hope it still works, I have yet to try it.