The rim cylinder, common to rim type deadbolts, nite latches and other rim locks. Some panic devices and other higher end hardware also use this type of cylinder. A die cast cylinder, (lower image) and solid brass cylinder shown here. You will find the die cast cylinders in hardware stores for as cheap as $5 - $10. The off brand solid brass cylinder goes for $15 - $20 or so. You may not find that at the home hardware, but it is certainly worth the extra $10. The name brand cylinders can be $40 or more. High security cylinders about $90 and up, with keys $10 or more. Rim cylinders are also available in Interchangeable Core (IC) type cylinders . On the panic bars that use these cylinders IC can be a good choice, considering how much hardware has to be removed to access the cylinder for rekeying.

  The cylinder typically comes complete with the rim cylinder ring, the backing plate, and 2 mounting screws. A 1-1/4" hole is used for the cylinder body. The mounting screws get carefully snapped off to the correct length with 2 pairs of pliers, bending the screw back and forth gently to fatigue it untill it snaps at the desired point. The cylinder and ring get passed through the outside of the door, the mounting plate and screws from the rear.