A tubular pin tumbler lock, also known as Ace lock; axial pin tumbler lock; or radial lock, is a variety of pin tumbler lock

Pin tumbler lock

The pin tumbler lock is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key...

 in which 6-8 pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape.

Joseph Bramah

Joseph Bramah

Joseph Bramah , born Stainborough Lane Farm, Wentworth, Yorkshire, England, was an inventor and locksmith. He is best known for having invented the hydraulic press...

 is credited with the invention of the forefather of the tubular pin tumbler lock except his used iron wafers not cylinders (red and blue in diagrams). He received a patent for his new lock in 1784. J.A. Blake is credited with patenting the first tubular lock in 1833. Walter R. Schlage continued the development of the tubular lock. He was awarded 11 patents.

Tubular locks are commonly seen on bicycle lock

Bicycle lock

A bicycle lock is a physical security device used on a bicycle to prevent theft. It is generally used to fasten the bicycle to a bicycle stand or other immovable object....

s, computer locks, elevators, and a variety of coin-operated devices such as vending machine

Vending machine

A vending machine is a machine which dispenses items such as snacks, beverages, alcohol, cigarettes, lottery tickets, consumer products and even gold and gems to customers automatically, after the customer inserts currency or credit into the machine....

s, coin-operated washing machines, and slot machines.

Security

Tubular pin tumbler locks are generally considered to be safer and more resistant to picking than standard locks, though there are several ways to open them without a key. Even though the pins are exposed, making them superficially easier to pick, they are designed such that after all pins are manipulated to their shear line, once the plug is rotated to around, the pins will fall into the next pin's hole, requiring re-picking to continue. As such, picking the lock without using a device to hold its pins in place once they reach their shear line requires one complete pick per pin.

Such locks can be picked by a special tubular lock pick

Tubular lock pick

A tubular lock pick is a specialized lockpicking tool used for opening a tubular pin tumbler lock. Tubular lock picks are all very similar in design and come in sizes to fit all major tubular locks, including 6, 7, and 8-pin locks....

 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 sizes are 0.375 in (9.5 mm) diameter and 0.394 in (10 mm) diameter. To prevent drilling, many tubular locks have a middle pin made of hardened steel, or contain a ball bearing in the middle pin.

In 2004, videos circulating on the Internet demonstrated that some tubular pin tumbler locks could be easily opened with the shaft of an inexpensive ballpoint pen (e.g., Bic pen) of matching diameter. Trade website BikeBiz.com revealed that the weaknesses of the tubular pin tumbler mechanism had first been described in 1992 by UK journalist John Stuart Clark (see Kryptonite lock

Kryptonite lock

The Kryptonite lock is an Ingersoll Rand-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...

).