Cylindrical lock is also known as “round lock”，“knob lock” since two perpendicular holes are bored into the door prior to installation.
it’s the most common lock type，can be quickly installed and replaced，also be rekeyed easily.
It always come in variety of finish（black，sliver，antique，golden），door thickness（35-55mm） and strike options，keying requirements can be accommodated.
All common lock function are available on cylindrical locks.
2.Cylindrical locks are sold in two grades：grade 1 heavy duty and grade 2 standard duty. Both grades are significantly tougher than common residential “tubular”locks。They can also be fire rated，which is usually not possible for tubular locks.
The heavy use and high abuse environment such as school ，hospital and sports stadiums can take their toll on even the best cylindrical lock.