Principles of operation
- See also: Pin-Tumbler (Principles of Operation)
The lock contains six pin stacks. Its most distinctive feature is the use of multiple diameter keypins, which together with a special warding causes the key pin tips at rest aren't at the same level (sometimes referred to as "shadow drilling"). These features provide additional resistance to key bumping attacks. The pin stacks alternate between serrated and spooled drivers, but due to the way the key pins rest in the chambers, the spools effectively engage only when paired with three shortest key pins. All of the drivers have slightly tapered tips, which gives this lock its bad reputation among the locksport community. The warding is not very restrictive and the keyway itself is not paracentric.
To disassemble a double euro cylinder, use of a pinning shoe is the preferred method.
Other possibility is to use a segmented follower, but that requires that both cores are pulled out a bit to allow a cam removal. Then a core should be rotated to approximately 4:30 or 7:30 o'clock position (135 degrees either clockwise or anti-clockwise) to prevent driver entering a gaps for the cam clutch. Then a segmented follower can be used to remove the core.
The Nemef NF2 is vulnerable to one or more of the following:
- Key bumping (It is resistant to but theoretically possible to bump this lock)