GMS COL6-3 Hardened Tapered Collar With Spring Washer and Spacer for Mortise Cylinders, Polished Brass

The GMS COL6-3 is a heavy-duty security accessory designed to protect mortise and rim cylinders from forced removal and tampering. It features a hardened steel construcción with a tapered profile that fits directly behind the cylinder housing and supports free-spin protection. Included in the package are a spring washer and a solid 1/8″ spacer to ensure proper fit and alignment. The unit is 9/16″ deep and supplied in an architectural polished brass finish US3 to match high-end hardware. All GMS collars are engineered for standard mortise cylinders and mortise T-turn cylinders, making this a versatile upgrade for commercial and institutional installations.

Key Features

• Hardened steel collar for high resistance to wrenching and forced cylinder removal.

• Tapered design fits snugly behind standard cylinders, reducing visible hardware and improving security aesthetics.

• Includes a spring washer and a 1/8″ solid spacer for proper spacing and retention.

• Depth: 9/16″, designed to fit standard mortise cylinder preparations with minimal modification.

• Finish: Polished Brass US3 / 605 — ideal for architectural hardware match.

• Installation: Directly mounts behind the cylinder, compatible with mortise or rim installations needing enhanced protection.

Why It Matters

In high-security or high-traffic doors, the cylinder is often the weakest link. By installing the COL6-3 hardened collar, you significantly increase the resistance of the cylinder to being pulled or torqued free, which helps protect against unauthorized entry or vandalism. The included washer and spacer simplify installation and ensure the correct alignment, saving time and reducing field errors.