For rim and mortise cylinders, a threaded set screw cap adds additional security to the cylinder. The set screw cap design prevents the pin stack from being forced up, and out the top of the cylinder during an attack (comb attack). The threaded set screw design also offers additional benefits.

From a servicing stand point, when a cylinder needs to be rekeyed, the entire pin chamber cover does not need to come off - only the pin chamber that needs to be rekeyed needs to be serviced. Also, cylinders with individually capped pin chambers do not require the use of a plug follower. This design increases maintenance and service productivity, and will drastically cut down on the time that it takes to rekey a cylinder and reestablish security.

Language to use in key system specification:
The manufacturer’s non-interchangeable core rim and mortise cylinders shall be so constructed to use threaded set screws, not staked covers or caps, to cover each individual pin chamber.