Cylindrical Knob Lock: The Round Lock That Fits the Standard Door Prep

A cylindrical knob lock is the round lock that slides into the two holes drilled in the door: the large bore for the body and the small edge bore for the latch. It is the standard residential and light commercial lock. It goes on bedrooms, bathrooms, offices, and front doors. The cylindrical body holds the cylinder, the spindle, and the latch mechanism. The knob turns, the latch retracts, the door opens. For builders and property managers, the cylindrical lock is the hardware that fits the door prep that is already there.

The Two Holes That Define the Lock

The cylindrical lock is named for the shape of its body. It is a cylinder that passes through the door from one side to the other. The body sits in the cross bore, the large hole drilled through the face of the door. The latch sits in the edge bore, the smaller hole drilled into the edge. The two holes cross inside the door.

A cylindrical knob lock with the right backset aligns the body with the latch. The backset is the distance from the door edge to the center of the cross bore. The standard is 2-3/8 inches or 2-3/4 inches. The lock has to match the door.

The latch retracts into the edge bore. The latch face plate sits flush with the door edge. The strike plate on the frame catches the latch. The cylindrical knob lock is the system that fits the door that was drilled for it.

The Cylinder and the Chassis

Inside the cylindrical body, the chassis holds the cylinder and the spindle. The chassis is the mechanism that retracts the latch when the knob turns. The chassis has to be strong enough to take the torque of the turning and the force of the closing door.

The cylinder is the keyed part. It is a plug inside a shell, held by the pins. The key lifts the pins. The plug turns. The cylinder is the security. A cylindrical knob lock with a solid cylinder resists the picking and the forcing.

The spindle connects the two knobs through the chassis. The spindle is the part that twists. A cylindrical knob lock with a hardened spindle resists the twisting that breaks the cheaper locks.

The Functions and the Finishes

The cylindrical knob lock comes in the passage, the privacy, and the keyed functions. The passage has no lock. The privacy has the turn button and the emergency release. The keyed has the cylinder and the key.

The finish is the visible quality. Polished brass, satin nickel, matte black, chrome. A cylindrical knob lock with a quality plated finish holds its look through the hand oils and the cleaning.

The knob shape is round or the ball. The round knob and the ball knob both fit the cylindrical body. The cylindrical knob lock is the body. The knob is the shape on the end.

Here is what a cylindrical knob lock needs to deliver:

• Cylindrical body that fits the cross bore
• Latch that fits the edge bore
• Backset matched to the door prep
• Solid cylinder with the right pin count
• Hardened spindle
• Passage, privacy, or keyed function

The Rental, the Office, and the Home

The rental property uses the cylindrical knob lock because it fits the standard door prep. The landlord replaces the lock between tenants without redrilling the door. The keyed function controls the access.

The office uses the cylindrical lock on the interior doors and the entry. The privacy function on the restroom. The keyed function on the file room. The cylindrical knob lock is the standard commercial hardware.

The home uses the cylindrical lock on every interior door and the exterior. The builder installs the same lock throughout the house. The cylindrical knob lock is the hardware the homeowner already knows.

The Latch That Sticks

The latch sticks because the strike plate and the latch do not align. The door swelled or the frame moved. The cylindrical knob lock is only as good as the installation. The key sticks because the pins wore. The knob wobbles because the spindle is loose. The finish wears through because the plating was thin.

A cylindrical knob lock is the round lock that fits the standard door prep. The body goes in the cross bore. The latch goes in the edge bore. Choose the function the door needs, the backset the door has, and a lock with the solid cylinder. The door will open and the key will turn. That is the job.