How To Install A Commercial Mortise Lock？

Installing a new lock might seem like a job best left to professionals, but with the right tools and a clear set of instructions, you can tackle the installation of a commercial mortise lock yourself. This type of lock is popular for businesses because it offers robust security, with the lockset housed inside a deep pocket—or mortise—cut into the edge of the door.

While the process requires precision, it is a manageable project for anyone comfortable with basic woodworking and hardware installation. This guide will walk you through every step, from preparing the door to testing the final installation. Following these instructions will help you secure your property effectively and save on professional installation costs.

What is a Commercial Mortise Lock?

Before starting the installation, it's helpful to understand what makes a commercial mortise lock unique. Unlike cylindrical locks, which only require a couple of round holes, a mortise lock requires a rectangular pocket cut into the door's edge. The lock body, which contains the latch and deadbolt mechanisms, fits snugly into this pocket.

This design makes mortise locks incredibly durable and resistant to forced entry. They are commonly found in commercial buildings, schools, and hospitals where security and high traffic are primary concerns. The lock typically includes the lock body, trim (handles or levers), a strike plate for the door frame, and a keyed cylinder.

Tools and Materials Needed

Gathering your tools before you start will make the installation process much smoother. Here’s what you’ll need:

· Mortise Lock Kit: Includes the lock body, trim, strike plate, cylinder, and screws.

· Drill and Drill Bits: A power drill with various bit sizes, including a spade bit or auger bit for the main mortise pocket.

· Chisel Set: Sharp chisels (1/4-inch and 1-inch are common) are essential for cleaning up the mortise.

· Hammer or Mallet: To use with your chisels.

· Measuring Tape and Pencil: For accurate marking.

· Combination Square: To ensure your lines are straight and square.

· Screwdriver Set: Both Phillips and flat-head.

· Mortising Jig (Optional but Recommended): This tool simplifies cutting the mortise, ensuring a clean and precise fit.

· Safety Goggles: Protect your eyes from wood chips and dust.

How to Install Your Commercial Mortise Lock

Follow these steps carefully to ensure a secure and professional-looking installation.

Step 1: Mark the Door

Accurate measurements are the foundation of a successful installation. Your mortise lock kit will come with a paper template—do not lose this.

1.Determine Lock Height: The standard height for a door handle is around 36 inches from the floor. Mark this height on the edge of the door.

2.Position the Template: Align the template on the door's edge so the center line for the handle matches your 36-inch mark. Tape it securely in place.

3.Mark Drilling Points: Use a sharp pencil or an awl to mark all the drilling points indicated on the template. This includes the outline for the mortise pocket on the door's edge and the holes for the handle, cylinder, and mounting screws on the door's face.

Step 2: Cut the Mortise Pocket

This is the most critical step and requires patience. A mortising jig can make this process much easier, but it can also be done manually with a drill and chisel.

1.Drill a Series of Holes: Using a spade or auger bit that matches the thickness of the lock body, drill a series of overlapping holes along the marked outline on the door's edge. Be careful to keep the drill level and straight. Drill to the depth specified in your template.

2.Clean the Pocket: Use your chisel and mallet to carefully clean out the remaining wood between the holes. Work slowly to create a smooth, rectangular pocket. The lock body should fit snugly but not be forced. Test the fit frequently as you work.

3.Chisel the Faceplate Area: Once the pocket is complete, insert the lock body. Trace the outline of its faceplate onto the door's edge. Remove the lock body and use your chisel to create a shallow recess for the faceplate, so it sits flush with the door's edge.

Step 3: Drill Holes on the Door Face

Now, you'll drill the holes for the lock trim and cylinder.

1.Select the Right Bits: Refer to your template for the correct drill bit sizes for the handle spindle, cylinder, and mounting screws.

2.Drill the Holes: Carefully drill through the door at the points you marked in Step 1. Ensure you keep the drill perfectly straight to avoid misalignment on the other side. Drilling a small pilot hole first can help guide the larger bit.

Step 4: Install the Lock Body and Cylinder

With all the cuts and holes made, you can now install the main components.

1.Insert the Lock Body: Slide the lock body into the mortise pocket. Secure it by driving the two screws through the faceplate into the door.

2.Install the Lock Cylinder: Insert the keyed cylinder from the outside of the door through the large hole you drilled. It should engage with the lock body inside. Secure it with the set screw, which is usually located on the faceplate of the lock body.

Step 5: Install the Trim

The trim includes the handles or levers that operate the latch.

1.Install the Spindle: Slide the spindle through the square hole in the lock body.

2.Attach the Handles: Place the handles on both sides of the door, aligning them with the spindle and mounting holes. Secure them with the provided screws or bolts.

3.Test the Mechanism: Turn the handles to ensure the latch retracts smoothly. Use the key to test the deadbolt and lock function. Make sure everything operates without sticking.

Step 6: Install the Strike Plate

The strike plate is the metal plate that installs on the door frame where the latch and deadbolt enter.

1.Mark the Position: Close the door gently until the latch and deadbolt touch the door frame. Mark their positions.

2.Align the Strike Plate: Open the door and align the strike plate on the frame with your marks. Trace its outline and the openings for the latch and deadbolt.

3.Mortise the Frame: Chisel out a recess for the strike plate so it sits flush. Then, drill holes into the frame for the latch and deadbolt to extend into.

4.Secure the Plate: Screw the strike plate firmly into the door frame.

Step 7: Final Testing

The final step is to test the lock thoroughly. Close the door and check that the latch engages smoothly with the strike plate. Lock the deadbolt with the key and ensure it extends fully into the frame. Test the handles and key from both inside and outside to confirm everything is working correctly.

A More Secure Property Awaits

By following these steps, you have successfully installed a commercial mortise lock, significantly enhancing your property's security. Taking the time to measure accurately and work carefully will result in a professional-quality installation that provides lasting peace of mind. While the process is detailed, the reward is a durable and reliable lock that will protect your business for years to come.

Commercial Mortise Lock

UL certified mortise lock

Commercial Door Hardware