Best SFIC Keyway Pictures

[Nace]

Also can a best core be bummed? I was told yes but thought I would make sure

[demux]

Regarding bumping: in theory yes, in practice I've found it to be much more difficult than a typical pin tumbler lock. Reading other threads both here and on other forums, I think most people have found this to be the case. If combinated with OEM springs and 7 pins, there's a lot of spring pressure in these cores. That and the tight tolerances, and it always feels like I have to hit a bump key so hard that I worry about damaging or knocking off the circlip on the back...

Regarding making a control key: if the official system math was followed, then yes this is very possible. There's a well-known formula to do it based on some simple measurements. What keyway is it, and do you know if it's A2, A3, or A4 system? No offense, but having only 3 posts here in two years, to get someone here to actually do this you may need to provide a few more details on what this core is from, how it came into your possession, why you don't have the control key, etc...

[Evan]

Regarding bumping: in theory yes, in practice I've found it to be much more difficult than a typical pin tumbler lock. Reading other threads both here and on other forums, I think most people have found this to be the case. If combinated with OEM springs and 7 pins, there's a lot of spring pressure in these cores. That and the tight tolerances, and it always feels like I have to hit a bump key so hard that I worry about damaging or knocking off the circlip on the back...

Regarding making a control key: if the official system math was followed, then yes this is very possible. There's a well-known formula to do it based on some simple measurements. What keyway is it, and do you know if it's A2, A3, or A4 system? No offense, but having only 3 posts here in two years, to get someone here to actually do this you may need to provide a few more details on what this core is from, how it came into your possession, why you don't have the control key, etc...

@Demux:

With Best SFIC cores when they become worn from years of use or frequent use in a shorter amount of time, they become susceptible to a phenomenon called key picking. Especially in an A2 system, as the increment is 2 step. A key that is very close to the one pinned into the core may when inserted and removed rapidly a few times and then inserted while applying turning force manipulate a sheer line into occurring that does not correlate to the bitting on the key being used. The reason this happens has to do with the geometry involved with the slopes between adjacent bittings and the pins being caught at the right place to turn at the right time. You may have seen this yourself when you can turn a key in a lock that is not fully inserted (i.e. one or two bittings of the key are still visible outside the cylinder) in a lock that is master keyed.

~~ Evan

[demux]

Yeah I've seen this as well. I actually had a really interesting manifestation of it once where it set everything to the next higher shear line in the stack and so the user was able to pull out his change key with the core turned (this was a fairly uniformly cut key so obviously not a lot of really high ridges between cuts, but they were there). For some of the larger systems I maintain I also keep a control key cut a half step higher in each position so I can still remove the cores when they get really badly worn and recombinate them.