A tubular pin tumbler lock, also known as a circle pin tumbler lock, radial lock, or the trademark Ace lock popularized by manufacturer

Chicago Lock Company Chicago Lock Co. is a lock manufacturer, founded in Chicago in 1920. Since 1933, it has sold a tubular pin tumbler lock marketed under the registered trademark "Ace." Millions of Ace locks have been sold; for instance, these locks are used in No ...

since 1933, is a variety of pin tumbler lock in which a number of pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape. Most locks use between six and eight pins, although some use as few as four or as many as ten. The devices have been widely used on vending machines,

elevator An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They ...

s, public computers, and bicycle locks.

Design

The design of a tubular lock is similar to the pin tumbler lock, in that there are several ''stacks'' of pins. The key is a cylinder shape with notches cut around the outer or (rarely) inner edge. Each of these notches depresses a single pin inside the lock to a specific height allowing the ''lock cylinder'' to turn freely.

Uses

Tubular locks are commonly seen on bicycle locks (such as the

Kryptonite lock Kryptonite is an Allegion-owned brand of bicycle lock for securing a bicycle to a pole or other fixture, when the owner wants to leave the bicycle in a public place. The basic design, made of hardened steel of circular cross section bent into a ...

), Kensington computer locks, elevators, and a variety of coin-operated devices such as

vending machine A vending machine is an automated machine that provides items such as snacks, beverages, cigarettes, and lottery tickets to consumers after cash, a credit card, or other forms of payment are inserted into the machine or otherwise made. The fi ...

s, and coin-operated washing machines. Tubular pin tumbler locks are often considered to be safer and more resistant to picking than standard locks. This is primarily because they are often seen on coin boxes for vending machines and coin-operated machines, such as those used in a laundromat. However, the primary reason this type of lock is used in these applications is that it can be made physically shorter than other locks.

Vulnerabilities

Such locks can be picked by a special

tubular lock pick Lock picking is the practice of unlocking a lock by manipulating the components of the lock device without the original key. Although lock-picking can be associated with criminal intent, it is an essential skill for the legitimate profess ...

with a minimum of effort in very little time; it is also possible to defeat them by drilling with a hole-saw drill bit. Standard tubular-lock drill bit diameters are and . To prevent drilling, many tubular locks have a middle pin made from hardened steel or contain a ball bearing in the middle pin. Some tubular locks, such as those used on older models of Kryptonite-brand bike locks, can be opened with the back end of a ball-point pen.

References

{{Locksmithing Locks (security device)

Design

Uses

Vulnerabilities

See also

References