Chubb 3G110 - how many differs?

by **greyman** » 20 Feb 2006 7:23

The sales documentation for Chubb locks says that the 3G110 5 detainer lock has around 25000 key differs and the 3G135 around 75000.

As far as I know these are double sided locks, so the keys are symmetric. There are 9 cut positions to operate the 5 levers from either side of the lock, hence 5 depths can be chosen and the other 4 follow from symmetry. With 9 depths of cut, you get 9*9*9*9*9=59049. This gets reduced to 25000 usable differs.

I guess the 3G135 must have an extra depth of cut to make it 10 depths. Since then you get 10*10*10*10*10=100,000 differs, reduces to 75000 usable differs. Can someone confirm this for me?

Also can someone tell me what the keying rules are (MACS etc)?

by **Shrub** » 20 Feb 2006 8:31

Macs arent a problem on lever locks due to the way they work, you can have any lever depth next to the other, the only rule is the one you know and that is to make them work from both sides.

The 110 has 9 differant lever heights,
The old 114 has 7 lever heights,
The new 114 has 8 lever heights.

The 7 lever locks obviously gets the extra combos from the 2 extra levers.

Hope this helps.

by **pizarro** » 20 Feb 2006 9:38

so, what is the largest difference in the key cut from 1 pin to the next?

basically can you have a '9 1 9 1 9 ' key cut?

by **Shrub** » 20 Feb 2006 9:58

Yes you can have the higest leverlift next to a lowest one, the way a lever lock works is by turning the key into the levers, a big reason for having macs on a cylinder lock is due to the key getting stuck if they have macs set like you can in a lever lock.

by **quacking_duck** » 20 Feb 2006 10:11

The 3G135 is in effect the same lock as the 110, 5 detainers and 9 differs per detainer. The only difference is in the curtain. It has 75,000 rather than 25,000 possible differs as there are 3 different profiles of the RKS curtains and keyblanks, which, in the main, are only available from Chubb, Chubb Supercentres etc.

The 3G135 can not be decoded with the SV 110 pin and cam as a result of this RKS curtain.

As a general rule, although possible, there would not usually be three adjacent depths the same on a new type 114 when it leaves Chubbs, although there may have been on the old type. You would not normally have even 2 adjacent depths the same on a 110, when it is produced although perfectly possible and it works the same as anything else if you rekey it. A 91919 cut is just likely as anything else.

The usual Chubb keying on 110s are therefore 9*8 (as the detainers won't usually repeat themself), then by 7*7*7 as the detainers are unlikely to repeat themselves to the cut of either of the adjacent detainers on each side. 9*8*7*7*7 = 24696. The extra combinations will be where, for example, detainers 2 spaces away from each other are identical, so the one in the middle has 8 further possibilities rather than 7, bringing it in above the 25,000 mark. However, keys, for example, 12121 or 98989 etc. would be avoided for the sake of the lock's security, as a lock with worn detainer gates may then allow the sidebar to pass into the gates with a keyblank or filed down one.

The 3G117 only has 6* more possibilities than the 114 as the 'ABBA' symettrics on the 7 lever key will only have the same no. of differs as the 'ABA' pattern on the 5 lever key for the 114, but there are 3 additional levers instead of 2. In effect multiplying the keying possibility by 8.
However, again, this is reduced to *6 to allow for the fact that 3 adjacent levers in the 117, like the 114 would not normally be identical when leaving Chubbs.

by **pizarro** » 20 Feb 2006 10:37

I must of missed the bit talking about level locks, I was refering to pin tumblers.

by **quacking_duck** » 20 Feb 2006 13:24

greyman wrote: With 9 depths of cut, you get 9*9*9*9*9=59049. This gets reduced to 25000 usable differs.

I guess the 3G135 must have an extra depth of cut to make it 10 depths. Since then you get 10*10*10*10*10=100,000 differs, reduces to 75000 usable differs. Can someone confirm this for me?

Sorry to go on about 110s etc., I was just answering original post and thought you meant would this key be possible on a 110

. In pin tumbler locks, you wouldn't have 91919, as the #1 cuts on the key would stick on the #9 pins and either wear the pins / key out or key may jam in the keyway.

by **greyman** » 20 Feb 2006 19:34

Thanks for the information everyone. So to confirm: the 3G135 is a glorified 3G110 with 9 depths of cut and 3 different curtain profiles, each one giving 25000 differs. My first suspicion was that Chubb allows 10 depths of cut on the key instead of 9, which would give 100,000 differs, reduced to 75000 after weaning out the impractical ones.

It seems like a bit of a strech calling keys with different profiles "differs". By this argument, the EVVA 5 pin system must have millions of differs since it has thousands of different key profiles.

I still have trouble imagining that Chubb would cut a 191919191 key. Surely it would break too easily?

by **quacking_duck** » 20 Feb 2006 21:51

I've known Securefast keys with HLH lifts to break in worn locks, as although they also use a 9 cut key, the mirror of the high cut, which is always present in L1 or 2, engages the bolt talon instead of the curtain throwing the bolt. Keys breaking in a 110 would be rare unless badly cut.

I agree with you that the Evva cylinders have far more possible keying combinations if you count the numerous profiles as extra combos, but as far as security goes and my personal preferences, I'd still choose the mighty Chubb 110 series any day against the vast majority of cylinders / lockcases on the market.

Regards,

Matt