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Question Re: bump keys

PostPosted: Wed May 29, 2013 4:13 am
by Neilau
Is it necessary for a bump key to be cut to all 9s?

Being that the purpose is to “bump” all the driver pins above the shear line and all the driver pins, at rest, sit below the shear line.

Would a bump key cut to all 5s or 6s work better?

The pins would have a shorter distance to “jump”

Just a thought.

Neilau

Re: Question Re: bump keys

PostPosted: Wed May 29, 2013 4:38 am
by MBI
It depends on the bitting of the lock. It doesn't HAVE to be all 9s, but they do that since some locks out there for that keyway will have a pin chamber or two with a 9-length pin in them.

A bump key with all 5s should work fine, IF the lock you're using it on doesn't have any cuts deeper than a 5 depth. Otherwise, if you used a bump key cut to 5s, if you had any stacks that were a 6 or deeper, you'd be over-bumping the chambers with the longer pins. You'd be bumping the top pins out of the way, but at the same time you'd be bumping the bottom pins IN the way of the shearline. To put it in picking terms, you'd be over setting that pin.

That's why some people prefer their bump keys cut to about a 9.5 depth instead of a 9 since it can tend to work better on locks that have a 9 depth on one of the pin stacks.

Re: Question Re: bump keys

PostPosted: Wed May 29, 2013 7:27 am
by Neilau
Thanks MBI.

9.5 ..... never thought of that...... Yes!

That means that the key pins DO move and not just transfer momentum.

A case of the theory and the real world not being exactly "in sync."

A cylinder with a 9 cut or two would need a very light "bump"

Thanks for the 9.5.

Neilau

Re: Question Re: bump keys

PostPosted: Wed May 29, 2013 8:48 am
by GringoLocksmith
Image

Re: Question Re: bump keys

PostPosted: Wed May 29, 2013 4:24 pm
by escher7
Neilau wrote:Is it necessary for a bump key to be cut to all 9s?

Being that the purpose is to “bump” all the driver pins above the shear line and all the driver pins, at rest, sit below the shear line.

Would a bump key cut to all 5s or 6s work better?

The pins would have a shorter distance to “jump”

Just a thought.

Neilau



I recently ordered 2 keys from Bumpmylock for a Sargeant 6 pin and a Master M1 padlock. Neither works worth a damn. Admittedly the Sargeant has tough pins, with at least 2 security pins and changes from 1 to 7 bitting adjacent. In fact I haven't been able to pick the lock yet, even knowing the key! Why the Master doesn't work I don't know.

I do have a set of Weiser depth keys and while the 999 key won't open the Weiser lock I have, an 888 key bumps it easily. The problem with a 999 is that the pins must be thrown quite high, and if the pin depths are significantly different, you may not get them to the shear line all at once. Ideally one would use a bump key cut to the maximum depth of the lock only, but that isn't practical and of course you may not know the pinning arrangement. And as noted above if a pin is deeper than your bump key it won't work.

Personally I think bump keys are over-rated. If you can bump it you can probably pick it.

Re: Question Re: bump keys

PostPosted: Thu May 30, 2013 12:02 am
by Neilau
Thanks Guys.

I see it now.

I also go along with Gringo 7. There are quite a few locks that don't seem to bump.

I think the whole bump thing has been overhyped.

Back to the old ways.

There is no easy/fool proof way to open all locks. Bumping is just another tool in the arsenal.

When all else fails there is always the 'ole Angle Grinder!!!!

Neilau

Re: Question Re: bump keys

PostPosted: Thu May 30, 2013 12:17 am
by selim
Don't forget to file the shoulder of the key back a bit