Tubular & Radial Pin Mechanisms
Tubular locks (also known as ace locks or radial pin tumbler locks) arrange their pin chambers in a circular pattern around a central solid post, matching the circular key format.
Operating Mechanics
Figure 1: Front face circular pin arrangement and side cutaway showing axial pin movement across the vertical shear plane. Source & Reference: Chicago Lock Company Engineering Reference & TOOOL Documentation.
- Pin stacks travel parallel to the keyway axis (longitudinally) rather than perpendicular to the key blade.
- The key consists of a hollow cylinder with notched cuts along its outer rim.
- A rectangular alignment notch on the outer rim ensures proper rotational orientation over the central guide pin.
Common Applications
- Vending machines, laundry machines, and coin-operated equipment.
- Elevators, key-operated alarm switches, and emergency controls.
- Bicycle U-locks, motorcycle disk locks, and lock boxes.
- Computer chassis and physical cable locks (Kensington-style).
Applicable Bypasses & Tools
- Tubular Lock Pick (7-Pin / 8-Pin): Self-decoding pick with spring-loaded slip collars that automatically find the shear position as the tool is oscillated with light rotational tension.
- Impressioning: Aluminum foil or soft-material decoder keys that map pin depths under rotation.
- Decoding: Measuring depths of exposed pin faces with a stepped gauge.