Guide to GU Ferco Single Point Locks - Monolock vs Unicorn

Guide to GU Ferco Single Point Locks - Monolock vs Unicorn

This article pertains specifically to GU Ferco single-point locks. This article provided by All About Doors and Windows (http://www.allaboutdoorsandwindows.com) can help if you are trying to replace a single-point GU Ferco lock. If you have a lock that only locks in one position, please continue. If you are trying to replace the lock body of a multipoint lock, which locks in multiple positions along your door, the locks in this article will not work.

GU has discontinued their old-style, single-point locks. If you have an old or broken GU lock, it must be replaced with a new-style GU Ferco lock. Though the old-style and the new-style both serve the same function and are relatively interchangeable, there are some minor modifications that must be made to accommodate the differences between the old and new lock styles.

GU Ferco manufactures two types of new-style single-point locks:
  1. The Monolock: This is a Europa lock, meaning it places the key cylinder below the handle.
  2. The Unicorn Lock:This is a New Breed lock, in which the key cylinder is above the handle.

Both of these locks have identical features and functions (one deadbolt latch and one spring-bolt latch). However, there are some major differences in the sizes and shapes of these locks that you should be aware of before you purchase one.

Design

As mentioned before, the key difference between the Monolock and unicorn styles is the location of the key cylinder in relation to the handle. The Monolock is a Europa style with the key cylinder below the handle, and the Unicorn is a new breed style, featuring the handle below the key cylinder.

This difference in design doesn't affect the function of both locks. Both feature a dead bolt and a spring bolt, and both require a downward push on the handle in order to retract the spring bolt latch and open the door. Consequently, if either are installed upside-down or incorrectly, they won't work. You will need to remove your lock and start over.

However, the obvious difference is an important one. Unless you are installing a brand new lock in a brand new door, you already have holes where your old key cylinder and handle used to be. Unless you want to bore new holes and fill old ones, the easy solution would be to go with the lock that features the same handle-cylinder placement your door is already cut out for.

Backset Measurement

The backset on a lock is the distance from the edge of the door (front of the faceplate) to the center of the key cylinder. This measurement must be precise. Here's where the going gets tricky; while Monolock-style locks are available in a number of backsets, Unicorn-style locks are only available in 45mm. If your old-style lock was Europa style (key below the handle), you should be pretty set going with a Monolock. However, if your old-style lock was Unicorn style (key above the handle), unless it happened to be a 45mm backset, you might be in a bit of a tight spot. Your door may require cutting or drilling to fit a new GU Ferco lock.

Available Backsets
MonolockUnicorn
30mm (1-3/16in)45 mm (1-3/4in)
35mm (1-3/8in)
40mm (1-9/16in)
45mm (1-3/4in)
50mm (2in)
55mm (2-3/16in)

Faceplate Size

Another difference between the Unicorn and Monolock styles is the length of the faceplate, the piece of metal that is visible on the inside vertical edge of the door (where the deadbolt extends). Though the faceplates of both styles are the same width, the Unicorn style faceplate is 280mm (11”) long whereas the Monolock is 292mm (11-1/2”) long. The faceplates cannot be interchanged, and may require some chiseling if different lengths than the old-style lock you're replacing.

Lock Case Length

Going with the faceplate difference, the lock cases of Unicorn and Monolock styles also differ in length and depth, though not in width.

Monolock lock cases are 195mm (7-11/16”) long and vary in depth depending on the length of the backset. Note: on a Monolock, add 18mm to the length of the backset to determine the depth. For example, a Monolock with a backsest of 30mm will have a depth of 48mm (1-7/8”).

Unicorn lock cases are 186mm (6-5/16”) long and 64mm (2-1/2”) deep.

These are important measurements to take into consideration when switching from an old-style lock to a new-style one. These measurements will determine whether your new lock will fit in your old lock mortise. If the lock you order is deeper or longer than your previous lock, the lock hole will need to be chiseled out more.

Before ordering and changing an existing lock of any kind, be sure and understand what is needed to change from one lock to another.

Monolock and Unicorn are brand names used by GU and Ferco.

The above PDF Article pertains to the following parts:
40136 - GU Unicorn 45/92 Single Point Key ABOVE Mortise Lock, 1-3/4 Backset
40145 - GU Monolock 50/92 Single Door Lock, Key BELOW - Stainless Steel
40144 - GU Monolock 45/92 Single Door Lock, Key BELOW - Stainless Steel

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