Yes. The Design Hardware mortise cylinder is cut for the C keyway with a 6-pin plug, so it takes keys on the standard Schlage C keyway and drops into a mortise lock body prepped for a threaded mortise cylinder. It ships keyed different, meaning each cylinder has its own key change and is not keyed alike to anything else unless you have a locksmith re-pin them to a common key.

It is the cylinder length measured from the face of the cylinder to the back of the threaded body, which decides how far it projects through the door and lock case. Mortise cylinders step in 1/8 inch increments, so a 1-1/4 inch body is one step longer than the common 1-1/8 inch and suits a slightly thicker door or trim stack. Measure the existing cylinder before you order, since a body that is too long stands proud of the trim ring and one that is too short will not reach the cam drive.

No. Keyed different means every cylinder carries its own unique key cut, which is what you want for individual tenant doors or when each unit must stay separate. If you want one key to open a group of openings, you need keyed alike or a master keyed system instead, or you take these C keyway cylinders to a locksmith and have them pinned to your existing bitting.

No. A mortise cylinder threads into a mortise lock case and drives a cam; a rim exit device needs a rim cylinder with a tailpiece. For rim applications look at the Schlage 20-021 rim cylinder with a vertical tailpiece cam or the 20-022 with a horizontal tailpiece cam, or the Corbin Russwin 3070 6-pin rim cylinder housing with a 1-7/8 inch tailpiece.

If the lock body still throws and retracts fine and only the key side is worn, seized, or compromised, the cylinder is the part to replace. This is a replacement cylinder, not a complete lockset, so it comes without a lock case, trim, or strike. Match the existing cylinder's length and cam before you order, since the cam style has to suit your lock body.

The Detex MC65 is the nearest match in a different brand: it is a mortise cylinder with a Schlage C keyway in a 6-pin commercial configuration, the same keyway family and pin count as the Design Hardware 1-1/4" mortise cylinder, 6 pin, C keyway. The difference is length - the Detex MC65 is cataloged at 1-1/8", so if the lock case and trim were prepped for a 1-1/4" cylinder, the shorter Detex body will sit deeper in the collar and may need a spacer ring or a different cam reach.

For Adams Rite narrow stile hardware, the purpose-built part is the Adams Rite 4036 mortise cylinder, a Grade 1 five-pin cylinder rated down to a 1/2" minimum door thickness - the thin stile dimension the Design Hardware 1-1/4" mortise cylinder is not sized around. If the opening uses an MS1847 deadlock, the 4024 cylinder pull with trim plate mounting and the 4025 five pin cylinder pull with through-screws are the matched options, and the 4026 five pin cylinder pull is the version for the 5017 wood door deadlock.

The Corbin Russwin 1070 is a 1-1/4" 6-pin mortise housing supplied with an A01 cloverleaf cam, matching the 1-1/4" length and 6-pin build of the Design Hardware mortise cylinder. It is a Grade 1 series housing, so it is the one to specify when the lock case calls for a cloverleaf cam rather than whatever cam ships standard. Note the Corbin Russwin uses its own keyway family, not a Schlage C keyway, so it will not key alike with C-keyway cylinders already on the building.

Step up to a 1-1/2" body. The Corbin Russwin 1000 Grade 1 mortise cylinder is 1-1/2" long with an A02 straight cam, and the Corbin Russwin 1080 is a 1-1/2" large format interchangeable core mortise cylinder, 6-pin, built for Schlage L9000 mortise locks with an A01 cam. Thicker doors and deeper trim rosettes are the usual reason the 1-1/4" Design Hardware mortise cylinder comes up short - measure from the face of the trim to the cam pocket before choosing.

No, they are not interchangeable. The Design Hardware 1-1/4" mortise cylinder threads into a tapped cylinder pocket in a mortise lock case and drives a cam. A rim cylinder such as the Schlage 20-021 or 20-022 mounts through the door from the back with a tailpiece instead of a cam - the 20-021 uses a vertical tailpiece cam and the 20-022 a horizontal one - and is what a rim exit device takes. Confirm whether the existing lock is a mortise case or a surface-mounted rim device before ordering.

Go to an interchangeable core system. The Schlage 20-057-C is a full size interchangeable core cylinder in the C keyway, so it stays in the same keyway family as the Design Hardware C keyway mortise cylinder while letting a control key pull the core. BEST offers the 1C 5-pin standard core and the 1CB 150 series interchangeable core, and the 1CDF is a drill resistant patented 7-pin brass core in the 150 series. The tradeoff is that IC housings and cores are bought as a system, where the Design Hardware cylinder is a single self-contained keyed different unit.

Six finishes: US3 bright brass, US4 satin brass, US10B dark bronze, US26 bright chrome, US26D satin chrome, and US32D satin stainless. For a property manager matching a run of doors, US26D satin chrome and US10B dark bronze are the two that normally line up with existing commercial lever and exit trim.

It is a conventional 6-pin cylinder, so rekeying means taking the cylinder out and re-pinning the plug at a bench. If you want to change keying at the door in seconds without tools beyond a control key, you need an interchangeable core setup instead, such as a BEST 1C 5-pin core or the 1CB Peaks 150 Series core, or a Schlage 20-057 FSIC rim cylinder. Those are a different lock prep, not a straight swap for a threaded mortise cylinder.

A key-in-knob or key-in-lever lock takes a different cylinder body than the Design Hardware mortise cylinder, which threads into a mortise case. The Kaba Ilco 1539 is a key-in-knob and lever universal cylinder, the 1599 is a key-in-knob replacement cylinder, and the 1579 is a knob and lever cylinder made for Sargent locks. For Falcon, the A23161-05 G is a key in lever cylinder for the RU/T series, 6-pin G keyway, keyed different, supplied with 2 cut keys.

The Design Hardware 1-1/4" mortise cylinder is for a mortise lock case. For deadbolt openings, the Kaba Ilco 1549 is a key-in-deadbolt cylinder. On residential-style handlesets and deadbolts, Medeco offers the 1012040, a 6-pin lazy motion rim cylinder for Kwikset single cylinder deadbolts, the 1075127 5-pin rim type lazy motion single cylinder for handlesets and deadbolts, and the 1065140 5-pin retrofit cylinder for Arrow JL interconnected locks and Emtek handleset and deadbolt outside cylinders.

If the opening does not need to be keyed, a dummy body fills the prep without pinning. The BEST 12E series dummy rim cylinder has a 1-5/32" diameter and is a non-functioning filler, where the Design Hardware 1-1/4" mortise cylinder is a working 6-pin C keyway cylinder keyed different. Check the prep first - the 12E is a rim body, so it suits a rim cylinder hole rather than a threaded mortise pocket.

Emtek products take their own cylinder parts rather than a threaded mortise body like the Design Hardware 1-1/4" mortise cylinder. The Emtek CY4 cylinder is sold individually for Emtek hardware, and Medeco makes the 1065244, a 5-pin rim lazy motion rim type cylinder supplied with an Emtek tailpiece. Confirm whether the Emtek unit calls for a tailpiece-driven rim body before ordering a mortise cylinder.

The Design Hardware 1-1/4" mortise cylinder is stocked in US3 bright brass, US4 satin brass, US10B dark bronze, US26 bright chrome, US26D satin chrome, and US32D satin stainless, which covers the common brass, bronze, chrome and stainless trim families in one part number. By comparison, the Schlage 20-057-C full size interchangeable core is cataloged in 643E aged bronze. Match the cylinder finish to the lock trim rather than to the door, since the cylinder face sits in the rose or escutcheon.