Tubular pin tumbler lock

A tubular lock and key

A tubular pin tumbler lock, also known as an ace lock, circle pin tumbler lock, or radial lock, is a variety of pin tumbler lock in which six to eight pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape.

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 edge. Each of these notches depresses a single pin inside the lock to a specific height allowing the lock cylinder to turn freely.

Mechanism

The key pins (red) and driver pins (blue) are pushed towards the front of the lock, preventing the plug (yellow) from rotating. The tubular key has several half-cylinder indentations which align with the pins.

The protrusion on top of the key fits into the rectangular recess in the lock, causing the indentations to properly align with the pins. When the key is inserted, the gaps between the key pins (red) and driver pins (blue) align with the shear plane separating the plug (yellow) from the outer casing (green).

With the pins correctly aligned, the lock may turn.

Uses

Tubular locks are commonly seen on bicycle locks (such as the Kryptonite lock), Kensington computer locks, elevators, and a variety of coin-operated devices such as vending machines, and coin-operated washing machines.

Tubular pin tumbler locks are generally considered by the general public 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 used in a laundromat. However, the primary reason the locks are used in these applications is their lack of the depth requirement that most other locks require.^[1]

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 0.375 in (9.5 mm) and 0.394 in (10.0 mm).^[2] To prevent drilling, many tubular locks have a middle pin made from hardened steel or contain a ball bearing in the middle pin.

Tubular locks, used on kryptonite bike locks, can be opened with the back end of a ball point pen,^[3][4] because they only used two pins.

See also

• Kryptonite lock
• Pin tumbler lock
• Tubular lock pick
• Wafer tumbler lock

References

Locksmithing & Lock picking
Topics	Electric strike Key control Key relevance Lock bumping Lock picking Lockout-tagout Maison key system Rekeying Single-point locking Three-point locking
Components	Bitting Bolt stump Break Interchangeable core Key blank Key code Keyhole Lockset Shear line Split pin
Key types	Berlin key Bump key Change key Master key Skeleton key Smart key Tubular key Transponder key
Mechanical Locks	Bored cylindrical lock Bramah lock Cylinder lock Disc tumbler lock Key retainer Lever tumbler lock (Chubb detector lock) Magnetic-coded lock Magnetic keyed lock Mortise lock Padlock Combination lock Rotary combination lock Time-delay combination locks Pin tumbler lock (snib) Protector lock Relocking device Time lock Tubular pin tumbler lock Warded lock Wafer tumbler lock
Electronic Locks	Electromagnetic lock Electronic lock Electric strike Magnetic-coded lock Keycard lock Electronic/digital-cylinder pin tumbler lock
Specific lock types	Bicycle lock Chamber lock Child safety lock Dead bolt Keycard lock Kensington Security Slot Luggage lock Power door locks The Club TSA lock
Tools	Lockpick Slim Jim Snap gun Tubular lock pick
Related	Bolt cutter Door chain Exit control lock Famous locksmiths Interlock (engineering) Keychain Key (engineering) Lock manufacturers Lock puzzle Lock snapping Locksport Two-man rule
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