keying-systems

Side-Bar Locking Mechanisms: Secondary Sidebar Verification in High-Security Cores

Engineering Overview: Engineering breakdown of secondary side-bar locking mechanisms, detailing true and false slider gates and rotational plug deadlocking.

Technical & Engineering Specifications

Gates True Gates with Anti-Pick False Gates
Standard EN 1303:2015 Attack Resistance Grade D
Mechanism Dual Pin Tumbler + Hardened Steel Side-Bar
Pick Resistance Immune to standard bump keys and pick guns
Sidebar Material Hardened 40Cr Alloy Steel (60 HRC)

The Dual-Verification Principle

High-security cylinders supplement standard pin tumblers with an independent Side-Bar Locking Mechanism.

Mechanical Operation

  1. Solid Steel Side-Bar: A hardened steel bar ($1.5\text{ mm} \times 25\text{ mm}$) sits in a groove along the side of the cylinder plug, protruding into the body housing to mechanically block rotation.
  2. Slider Alignment: Inserting the correct key positions internal rotating wafers or sliders so their true gates align precisely with the side-bar teeth.
  3. Sidebar Retraction: When aligned, rotational torque forces the side-bar into the slider gates, allowing free plug rotation.

Frequently Asked Engineering & Selection Questions

Q1: How does a side-bar lock prevent picking?

Even if the top and bottom pins are picked to the shear line, the solid steel side-bar physically deadlocks the plug until all sliders are aligned.