FAB 3***/4****

=FAB 3*** Profi and 4****=

FAB 3*** Profi and FAB 4**** are two new locks from FAB; FAB 3*** Profi belongs to a resistance class 3, FAB 4**** belongs to resistance class 4. These locks differ quite significantly from the previous FAB's products - both of them are six pin locks, they have a new key shoulder and shoulder stop, new pins, different cam clutch and more...

Description
Both locks are quite similar - FAB 4**** just seem to be using different keyway, core contains six more antidrill inserts and by default it contains a cam clutch allowing unlocking even when a key is inserted from the other side. Both locks have six pin chambers, equipped with a new style pins - both keypins and drivers are thinner than in previous generations of FAB locks, keypins have even slimmer tops (no reason for that mentioned in patents or documentation). Driver pins seem to be reworked too and the thinner spools don't cause much counter-rotation, when a false set is achieved, adding to the improved picking resistance. Also springs are different and quite a bit stronger than in previous locks.

Pinning "structure" is also different compared to older top models - there is only sigle RBC pin, two spools and the rest are standard drivers (one brass, two steel ones in the back). The behavior of the lock changed too - the standard driver behavior is similar to the old beveled/tapered ones FAB used long time ago, which combined with the spools and the RBC pin improves the picking resistance further.

Key is also very different, and it contains interesting feature (patented) - the key shoulder has a shape that interfaces with a groove in the core. This shape can be used for master-keying purposes, as detailed in the EP3219882B1 patent.

Also the core clutch used in FAB 3*** Profi is completely different - it has no moveable parts and uses a groove milled in the back of the core to function.

Dissassembly instructions
The core has two groves for the cam clutch at 3 and 9'o clock positions, that would allow driver to jump out before the follower would hold it. Also the antidrill insert chambers of 4**** are wide enough to catch a driver, so a core rotation of more than say 100 degrees to either side should be safe. Pinning shoe can be handy, although you have to count with the stronger springs and smaller pin diameter. Segmented follower can be used for the double euro format too.

Vulnerabilities
The FAB 3*** Profi/4**** are vulnerable to one or more of the following:


 * Lockpicking
 * Decoding
 * Key bumping - when RBC pin is worked around
 * Impressioning