However, the design of the cylinder requires the use of special tools to manipulate the pins and apply torque. SFIC cylinders (such as those made by Best), used in large institutional lock systems, employ a similar mechanism to provide two kinds of keys: regular keys that operate the lock and control keys that unlock and remove the cylinder core itself. Master ring cylinders (which are no longer in common commercial production but were once marketed by Corbin) use this mechanism to provide independently-keyed master keying. The usual scheme for master keying involves using more than one cut in some or all pin stacks (this is accomplished by adding additional pin segments). The most common security pins are the "spool" and "mushroom" top pin designs, which are thinner in their mid-section. For example, Medeco locks use special wedge-shaped bottom pins that are rotated into one of several possible positions by the key cuts (which can be cut at different angles). Picking locks with spool and mushroom pins takes practice, both to recognize them and to effectively neutralize them when they are encountered. The first sign of spool and mushroom pins is that the lock will appear to be picked, but will only turn a few degrees.

Rubbing exploits this by simulating several passes of pin-at-a-time picking in a few "strokes" across the pin stacks. A few pin tumbler lock products orient the key horizontally in the keyway and use a flat key bitted with variable-depth holes ("dimples") rather than the cuts used for the familiar "sawtooth" key. In a lock with six pin stacks with a uniform chance of a pin setting at either shear line, the probability of a picked lock actually opening is only 1/64. Picking techniques for these locks involve the use of special torque tools designed to put torque on only one of the two concentric plugs. There are locks with two, five, and six pins in each keyway, but the keying codes aren't labeled on them. Master keying does not introduce any significant complications for lock picking. In fact, master keyed pin stacks are easier to pick than those that are single-keyed; there are two chances to lift a cut to the shear line.

As the peaks hit the pin stacks, energy is transferred from the bottom pins to the top pins, much like the action of the cue ball in billiards. When the energy transfers, the top pin moves up while the bottom pin slows down, and a gap is created between the two pins. Figure 7. LAB Serrated top pin. See Figure 6 for an example of a spool pin. These locks can be picked according to the same principles as used for ordinary pin tumbler locks, but, again, what is billiards different tools are used to accommodate the different shape of the keyway. Tubular locks suffer from the same manufacturing imperfections as other locks and so can be picked with essentially the same techniques. If you can pick all (or at least most) of the locks on this board, you are well prepared against the typical locks installed in residential and commercial buildings in the US.

These are typically pin tumbler locks, but their orientation is "upside down" with respect to the convention for locks installed in the United States. The game of carom billiards is still played primarily in France and other European countries and to a lesser degree in the United States and has many players in Japan, Indonesia, the Philippines, Taiwan, and South Korea and in Central America, South America, Africa, and the Middle East. Billiards is a cue sport played on a rectangular table with pockets, where players use cue sticks to strike balls into the pockets. The game of English billiards is played on a relatively large table, usually 6 feet 1.5 inches by 12 feet (1.9 by 3.7 m); it is played with three balls as in carom-a plain white, a white with a spot, and a red. The other principal games are played on tables that have six pockets, one at each corner and one in each of the long sides; these games include English billiards, played with three balls; snooker, played with 21 balls and a cue ball; and pocket billiards, or pool, played with 15 balls and a cue ball.