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 since 1933, is a variety of

pin tumbler lock The pin tumbler lock, also known as the Yale lock after the inventor of the modern version, is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employ ...

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 A vending machine is an automated machine that dispenses 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 payment is otherwise m ...

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

s, public computers, and

bicycle lock A bicycle lock is a security device used to deter bicycle theft, either by simply locking one of the wheels or by fastening the bicycle to a fixed object, e.g., a bike rack. Locking devices vary in size and security, the most secure tending to ...

Design

The design of a tubular lock is similar to the

, 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

s (such as the Kryptonite lock), Kensington computer locks, elevators, and a variety of coin-operated devices such as

vending machine A vending machine is an automated machine that dispenses 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 payment is otherwise m ...

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 A self-service laundry, coin laundry, or coin wash, is a facility where clothes and some household textiles are washed and dried without much personalized professional help. They are known in the United Kingdom as launderettes or laundrettes, ...

. 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 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