The key part of lockset--Cylinder, regarded as the heart of mortise lock, can rotate with key and drive lock pins to control door opening. Cylinder mainly consists of casing, plug, and pins.
There are many different optional functions for cylinder: key to key function (double cylinder), key to knob function (single cylinder), half cylinder, privacy function (bathroom), master key function, keyed-alike function, construction key function, and anti drill function.
Nine kinds of keyway are supplied including angle-cut-pin keyway, computer keyway, double-row-pin keyway, dual keyway (one side single-row pin, one side track-cut pin), Yale keyway, Kwikset keyway, Schlage keyway, and Weiser keyway.
As for surface finish, there are AB(Antique Brass), AC(Antique Copper), PB(Polished Brass), SB(Satin Brass), and SN(Satin Nickel).
Key to key function (double cylinder): 60mm, 70mm, 80mm, 90mm, 100mm
Key to knob function (single cylinder): 60mm, 70mm, 80mm, 90mm, 100mm
Half cylinder with turn knob: 40mm, 45mm, 50mm
Half cylinder with key: 40mm, 45mm, 50mm