The Rim Night Latch: What 564 and 1073 Actually Measure

A rim lock is a lock that does not go inside the door. The case screws to the inside face of the leaf, the cylinder passes through a single hole, and the latch engages a keep screwed to the frame rather than a mortised strike. Everything that follows from that is why a rim night latch is dimensioned differently from a mortise case, and why the numbers a buyer asks for are not the same numbers.

Start with backset, because it is the one that gets confused. On a mortise lock the backset is measured from the edge of the door to the center of the spindle. On a rim night latch it is measured from the edge of the door to the center of the cylinder hole, and on both our 564 and the 1073 it is 60mm (2-3/8"), 2-3/8 inches in the form a North American buyer will write it. That single hole is the whole of the door preparation, which is why a rim lock is the lock people fit to a door that already exists.

Door thickness is the next constraint, and it is a range rather than a figure: 35mm (1-3/8") to 55mm (2-3/16") as standard on both models, and 30mm (1-3/16") to 60mm (2-3/8") on request. The range exists because the cylinder tail bar has to reach the mechanism, and a cylinder too long for its door leaves the lock proud and the fixing loose. If your leaf is outside 35 to 55, say so in the inquiry rather than at the packing stage.

Two throws matter and they are not the same throw. The latch extension is 13mm (1/2") (that is the sprung latch that closes the door behind you) and it carries an inside deadlocking button, which is the part that turns a night latch from a door-closer into a lock. The deadbolt throw is 25mm (1") on the rim deadbolt versions, and 25mm (1") is the figure a specification usually means when it asks for a full-throw deadbolt on a rim lock.

Handing is the question a rim lock mostly does not have. Both models are fully reversible, left or right hand, which on a lock that mounts to the face rather than into the edge is a matter of assembly rather than of a different part number. What is not reversible is the strike: an angle strike is standard for an inward-opening door, and a flat strike is available. Ordering the wrong one is a site problem, not a factory one, so it belongs in the schedule.

The 564 and the 1073 differ in the metal, and the difference is stated rather than implied. The 564 is a zinc die-cast case with zinc-plated steel internals, a brass thumbturn button, a brass cylinder core and an aluminum cylinder housing. The 1073 is an iron case with zinc-plated steel internals, a brass rolling latch, a brass cylinder, and it ships with three brass keys. Both are residential-to-light-commercial locks; neither is presented here as a high-security product, and a project that needs one should be asking about a mortise case instead.

The choice buyers actually have to make is 1073S against 1073D: single-side opening against double-side. A single-side night latch is opened by key from outside and by knob from inside, always, with no key required to get out. A double-side version needs a key on both faces. That second arrangement is more secure against somebody reaching through broken glass and less safe in a fire, and in many jurisdictions it is not permitted on a final exit door at all. It is a decision about the building, and we will supply either, but it is not a preference.

One feature is worth naming because it is easy to skip in a specification: an anti-picking slide gate on the single-cylinder deadlock. That is a mechanical obstruction in the case rather than a property of the cylinder, so it is independent of whichever cylinder you key the lock with, and it is the kind of thing that does not show up in a photograph. If you are comparing our 564 against a competitor's night latch, that row is worth comparing directly, because catalogs tend to state it only when they have it.

The rest of the family, and what actually differs

The 564 and the 1073 are the two most asked-about, but they sit in a family of rim locks that share far more than their model numbers suggest. Across the 260, 556, 558, 559, 5681, 5682, 5683 and the two models above, the published core is the same: a 60mm (2-3/8") backset, a 35–55mm (1-3/8" to 2-3/16") door as standard and 30–60mm (1-3/16" to 2-3/8") on request, a 13mm (1/2") latch with an inside deadlocking button, a 25mm (1") deadbolt throw on the rim deadbolt versions, an angle strike as standard, full reversibility and the anti-picking slide gate. That common core is useful: it means a door prepared for one of them is prepared for the others.

What separates them is published in the rows that are not shared. The case metal: iron on the 260, 556, 558, 559, 5683 and the 1073, zinc die-cast on the 564. The latch metal: brass on the 5681, zinc alloy on the 5682, both otherwise in iron cases with three brass keys. The latch form: the 558 and the 564 are published with a bevelled latch structure. And the opening: the 1073S is single-side, while the 1073D, 5681, 5682 and 5683 are published as double-side. The 5688 is the odd one out, an iron case published at 100 × 100mm (3-15/16" square) as double cylinder, double throw.

Three functions are published across the family: single cylinder, double cylinder and self-locking. The first two are the single-side and double-side choice described above. Self-locking is the listing's term, and it is exactly the kind of word that means slightly different things in different markets, so if it matters to your door, ask what it does on the specific model rather than assuming the behavior of a lock you have fitted before.

Fitting: the tail bar and the screws

A rim lock is the lock people fit to a door that already exists, and two things decide whether that fitting is solid or merely attached.

The first is the tail bar, the flat bar on the back of the cylinder that passes through the door and turns the mechanism in the case. It is supplied long and cut to the door. Cut it too short and it does not engage; leave it too long and it pushes the case away from the door face. This is the practical reason the door-thickness range exists: 35 to 55mm is the span over which the standard parts work without special lengths, and the 30–60mm range on request is the same lock with a different tail bar and fixing length. Measure the leaf at the lock position, not at the edge, because a panelled or rebated door is often thinner where the lock actually sits.

The second is the fixings. The case screws into the face of the leaf and the keep screws into the frame, and neither is stronger than the timber it sits in. On a softwood frame the keep is the weak point of the whole installation, so use the longest screws the frame will take, and on a hollow or metal door confirm what the fixing will bite into before the order, because the answer changes the screws rather than the lock.

The strike decides the door's opening

As noted above, the angle strike is standard for an inward-opening door and a flat strike is available. The consequence is worth spelling out: a rim night latch is at home on an inward-opening door, where the angle strike wraps the frame edge and the latch engages it cleanly. On an outward-opening door the geometry changes, and the strike, the fixings and sometimes the lock choice itself change with it. State the opening direction on the schedule next to each rim lock, it costs a word and saves a site visit.

When a rim lock is the right answer

A rim lock is the right answer more often than its price suggests. It suits a timber door that already exists, a door where cutting a mortise pocket would weaken a thin stile, a secondary lock added to a door that already has a latch, and any job where the installer has one hole's worth of time rather than a mortise's. Where the family publishes an application at all, it is residential, the 1073 and 5683 say so directly, and the 564 MB is published for wooden and metal doors in homes.

It is the wrong answer where the door needs a rated lock, where the specification asks for a particular security grade, or where an authority wants a single-action exit on a final escape door and the proposed version is double-side. In those cases the conversation is about a mortise case or an exit device, and it is better to have it before the rim locks are on a container.

Ordering in quantity

One commercial row is published for the 564 and worth knowing early: a minimum order of 1,000 pieces. Other models in the family do not publish a minimum, which is not the same as having none, so if you are pricing a small project, ask for the minimum on the models you are considering in the same email as the price. Mixing finishes or functions within one order is a common question, and the answer depends on the model; say what mix you need and we will tell you what is possible rather than what is convenient.