Bump-keying an ASSA SCD- Is it even possible?

[zaphod_beeblebrox]

Hello everyone! I have been interested in locks and picking for quite some time, but it's not util a few months ago I really got started. So, now I've watched Toool's presentation of the "Bump-key" method whitch got my attention. I didn't really like the concept, because it didn't seem to require any skills whatsoever etc. But one day, I decided to try it out, and to my partly happy, partly sad surprise, it didn't work. I had gone to a locksmith and told him to make a key with as much metal cut away as possible. Thereafter, I filed the key ½mm on the shoulder and 2 mm off the tip. It didn't work. At all. Not even after like 300 strikes. So I filed the key to make the ^-shaped "hills"(what are these called, btw?) lower so that they would be just high enough to push the lower pins up. I think I filed the key pretty good, and it really should be working. I have read all the tutorials etc. and made the key according to all guidelines available. But the cylinder still refuses to turn, no matter how hard i strike it etc. Now, I wonder, is there some kind of "special" blocking-mechanism especially in the ASSA SCD (or in other locks) that would prevent a bump-key to turn the cylinder? Could it be a so-called "blocking-ball"? Anyone who has succeed with bumping this lock? If not, I guess I can sleep safe tonight, but I still wonder why it just will not open, when other people have succeeded picking it by hand. Thanks in advance
//Zaphod

[Wolf2486]

Is this one of the ASSA locks that have side cuts?

[zeke79]

I believe the SCD is a non sidebar 7 pin lock from assa. Though it does not incorporate a sidebar it is still a tough lock to pick and possibly even bump. This is due to the special shaped top spool drivers and the counter milling used in the plug to trap the special top drivers. The effect here locks the plug from turning and will not allow the top or bottom pins to be pushed any farther up in the plug. I believe there are 4 of these counter milled chambers in the plug along with 4 6 specially shaped top spool drivers and 4 specially shaped bottom security pins. I can post pictures of this later or you can refer to Han Fey's article on cutaway locks from Toool's website. It does not give a clear view of the counter milling in the plug but it does show the pins I am speaking of.

[digital_blue]

[off topic]Nice nickname. I love HHG. [/off topic]

[zaphod_beeblebrox]

Thanks a lot for all the answers. Really, I appreciate it.
Yup. I'm aware of those top-pins and i've seen them on pics etc. But, from the looks of it, they seem to only block the pins from being pushed up if there is tension in the cylinder. With a bumpkey, there is no tension until you turn it, and when you turn it the top pins should already be in place if you've hit it right. And since I turn right after I've hit it (and i've done this like a million times now, with different techniques etc.) it should open. And yes, it is 7-pin, and it is the absolutely most common lock in Sweden(in any case Stockholm) and I have it too. I also wonder how the heck some people have succeded picking it by hand?

[off-topic]Yeah. I really love HGTTG too[/off-topic]

[zeke79]

The next question would be is the lock clean? If the lock is sticky at all this is a problem while bumping. You are right however that if you are not applying tension before striking the key the security features of the lock are defeated. As far as picking the lock goes if the plug is in good condition it will be very difficult. If the plug is showing wear or has been filed by an inexperienced locksmith which I have seen before in some ASSA locks then the picking will become substantially easier.

[zaphod_beeblebrox]

The key was from the beginning filed by a very experienced locksmith. Though, because the key not working I myself filed it even more. Yes, you might be right about the lock. I'll check into that. Butthe problem is that iv'e tested on other locks aswell of the same type...