I removed a couple of springs, stretched them, and reassembled. I saw to it that the pins were polished and rode smoothly on the key.
That made it slightly more difficult to insert/extract the correct key, but the bump key no longer worked because bumping couldn't generate enough pin inertia to overcome the increased spring tension.
In and of itself probably not, although it might help slightly, it does not overcome the physics involved. There might be some benefit to playing with the point style on the pins. Try this, set up a cylinder with an assortment of traditional pointed pins, some Kwikset bull nose pins and one or two chambers with Russwin ball bearings and flat bottom pins.
By doing this you may be able to achieve enough timing variation so that if a person were to try to bump the shear line gap would be blocked by some pins on the down stroke while others were on the up stroke. You may have to spend a little time when generating change keys to accommodate this scheme by making a rounded cut for the balls a wider cut for the bulls and a standard cut for the points but you should end up with a smooth working key and a more difficult to bump lock.
But not where the secondary mechanism is 'keyed alike' as in ASSA (or derivatives such as Australian Lockwood twin) or Schlage Primus, as found in universities and the like or region covered by a prominent locksmith shop. Any stray related key can be made into a bump key with a reasonable chance of working.
I tried the stretched spring solution on a couple of locks and it worked fine. However, every lock and every bump key (with its own unique ramp and height of teeth) is a unique combination. Has anyone else tried this simple technique? If so, what results?
So you can't (according to you) bump key it but anyone with a clue what they are doing can still pick it faster than I wrote this, so what's the point?
I've only once had someone ask me about making cylinders more bump proof. And never had anyone ask about making them more pick proof. So, perhaps in the real world, it hasn't caught on?
Had a customer with the bump key problem.. (SON) tried the split top pins (added a small top pin above the standard one) I cut a bump key and still got it picked. tried stretching the springs and it slowed me down but the springs didn't keep the tension long and it finally bumped open. last but not least I added a couple mushroom top pins and still got it.. Damn it man! So I did all three methods together and finally couldn't bump 3 out of four locks. Just one gave in. Recommended to the customer I change all the locks to HS.
So the customer is waiting for the tax refund and I'm off to change all the locks!
The "point" is that any doofus with a bump key ($15 for a set of 6, online) can bump a lock open with no training, no clue. Picking --- now that's another story.
If you load two springs into a lock bad things are likely to happen. I believe that you are running the real risk of crushing the springs or forcing off the cap. There is only so much room and when you have a long pin all of this room is taken up when a high cut is inserted.
Hardly. Picking a kwikset usually amounts to nothing more than raking which anybody with about 60 seconds practice can do just fine. It's easier than bump keying. BY FAR.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.