Replacing or installing a new mortise lock? The key to a smooth process is accurate measuring. Here’s a guide to help you choose the right size lock for your door.
1. Know the Lock Type
There are two main types of mortise locks: deadlocks and sash locks. Deadlocks are common for front doors, while sash locks are typically used on back or interior doors. Deadlocks are easier to measure since they don’t require handle alignment.
2. Measure the Door Thickness
Mortise locks come in different sizes, so it’s essential to measure the thickness and width of your door stile. This ensures the lock fits properly without damaging the door.
3. Consider the Door Material
Mortise locks are only compatible with wooden doors. If your door is made from a different material like steel or fiberglass, consider other lock options.
4. Security Level
If you’re installing the lock on a front door, opt for a 5-lever mortise lock for added security. A 5-lever lock is more difficult to pick and provides better protection than a 3-lever lock.
5. Measure an Existing Lock
If you’re replacing a lock, measure the forend length and width (the part you see on the door’s edge). This ensures a precise fit for the new lock.
How to Measure
For a deadlock, take the following measurements:
• Backset: The distance from the door’s edge to the center of the lock.
• Case Depth & Height: These determine the space the lock will occupy in the door.
• Forend Length & Width: Visible parts on the door’s edge.
For sash locks, follow the same steps, but also measure the center where the spindle (door handle) passes through.
Accurate measuring helps you avoid door damage and ensures a perfect fit for your lock. Follow these steps to save time, money, and ensure proper security.