David Bolton What UL 437 Actually Tests: How High-Security Cylinders Earn Their Listing and Where to Spec Them Why the Cylinder Listing on a High-Security Door Matters More Than the Lock Body When a facility manager, security consultant, or commercial sub is spec-ing hardware for a server room, pharmacy, recor... Commercial Door Hardware Hardware Specification High-Security Cylinders Key Control UL 437 Jul 10, 2026
