Independent comparisons. We may earn from shop links. More info

Mortice or rim door knobs: which pair your door will take

Updated: October 2026

You have two round knobs that look alike in the photos, and a door that has either a narrow plate on the edge or a lock case on the face. Mortice or rim door knobs is that look test. The pairs are not interchangeable, and leaving a rose in the drawer does not convert one into the other when the rose is fixed. Shelf prices are on the [doorknob comparison](/hub/door-and-window-security/doorknob). Spindle, spring and finish stay on the [doorknob buying guide](/hub/door-and-window-security/doorknob/sub/doorknob-buying-guide). Peter F. used UK ironmongery explainers and the kept amazon.co.uk listings, updated October 2026. A qualifying purchase can earn a commission at no extra cost to you.

You have two round knobs that look alike in the photos, and a door that has either a narrow plate on the edge or a lock case on the face. Mortice or rim door knobs is that look test.

Our top picks

Infinity Decor Infinity Victorian brass knobs, 52 mm

Best overall

Infinity Decor Infinity Victorian brass knobs, 52 mm
7.8/10about £16.95
View offer
HANDLESTORE Handlestore polished chrome sprung pair

Rank 2

HANDLESTORE Handlestore polished chrome sprung pair
8.6/10about £10.99
View offer
Sterling Sterling SRL8BK black rim pair

Best value

Sterling Sterling SRL8BK black rim pair
8.2/10about £6.99
View offer
On this page
  1. 1.Look at the door, not the photo
  2. 2.When the mortice pair is the one
  3. 3.When the rim pair is the one
  4. 4.The condition

Look at the door, not the photo

Stand on the side you normally open. A rim lock is a case screwed to the face of the door, with a keep on the frame. A mortice latch or sashlock is buried in the edge. What you see is a thin plate on that edge, and a spindle hole through the stile. Suffolk Latch uses that same glance: visible case, or a latch in the edge. The knob’s job is to turn the latch. A keyhole in a rim case does not mean the knobs themselves are a keyed set. A Victorian internal door can be either. Panels and architrave do not decide it. The test is the case you can see today, including a case that was added later. If you are still looking at product photos, you are guessing.

When the mortice pair is the one

Choose a mortice pair when the latch is in the edge and you need a rose on both faces. The spindle runs through the follower, and each knob is screwed to the timber. In this comparison that is the Handlestore polished chrome sprung pair, the top pick, the XFORT mushroom knobs, and both Infinity brass pairs. None of those boxes names a latch. The Victorian brass pair prints an 8 mm spindle. A strong spring is a reason to pause after you have picked mortice, not a reason to switch to a rim set. The best doorknob page puts a price on each of them. If the follower will not take the bar, you fix that on the mortice side. You do not solve it by buying rim knobs.
Infinity Decor Infinity Victorian brass knobs, 52 mm

Testsieger

Infinity Decor Infinity Victorian brass knobs, 52 mm
7.8/10about £16.95
View offer

When the rim pair is the one

Choose a rim pair when the lock case is on the face. The spindle has to pass through that case, and the rose on the lock side is left off, because the case occupies the place a rose would sit. More Handles describes a rim knob with no rose on the lock side. You measure the backset of the rim lock you already have, not the backset of a tubular latch from a different door. The rim listing here is Sterling’s SRL8BK, the best value, a 45 mm black pair at about £6.99, sold for rim locks and rim sashlocks. The knobs are smaller than many people expect, and two reviews call the set plastic. It does not include the lock case. Skip this pair if your only metal is a latch plate on the edge.

The condition

Buy the pair that matches the case you can see, and only if the roses can be arranged the way that case demands. Mortice wants two roses. Rim wants the lock-side rose omitted. Trade sets exist with loose roses so one can be discarded. Those sets are not among these eleven listings. Handlestore’s knob covers the screws. Infinity calls the Victorian rose inseparable. Do not snap a rose off to force a mortice pair onto a rim lock. An 8 mm mortice bar will not rescue a 7 mm rim follower, and a 45 mm rim knob will not give you knuckle clearance on a short mortice latch. If those numbers are still open, go back to the buying guide before you order. A keyed ball set and a dummy are neither of these pairs.

Common questions

How do I tell a rim lock from a mortice latch without taking the door off?
Look at the face and the edge. A box screwed to the face, meeting a keep on the frame, is a rim lock. A narrow plate on the closing edge, with the mechanism inside the stile, is a mortice latch or sashlock. You do not need to lift the door off its hinges to see that.
Can I use a mortice pair on a rim lock if I leave one rose in the drawer?
Only if that rose is loose and the listing tells you to omit it. The mortice pairs in this comparison do not say that. Fixed roses, and knobs that hide the screws, stay on both sides. Forcing one off is how the finish and the fixing get damaged.
Do rim knobs include the lock?
This rim pair does not. The bullets name knobs, a spindle and screws for a rim lock you already have. The lock case and the keep stay on the door. If the case itself is broken, knobs will not replace it.
What fails if the spindle is for the wrong follower?
The bar will not enter, or it will be slack. Modern mortice latches are commonly 8 mm. One Sterling review describes a 7 mm fit on an older sash rim lock. A thick bar that reviewers file, on the mushroom knobs, is the same mismatch from the other direction.
Which one needs the longer backset for knuckles?
The mortice knob on a round rose, because your hand swings close to the frame. Trade notes put a practical minimum near 57 mm from the edge to the spindle centre. A rim lock has its own backset, measured on the case, and the lock body already holds the knob off the face.
When is neither of them the right buy?
When the door has no latch and only needs a pull, or when you need a keyed latch set rather than furniture for a lock you already own. A fire door or a final-exit lock is a joiner’s specification, not a choice between these two pairs.

Related pages

How to fit a doorknob

Doorknob

Bathroom door knob: privacy without trapping someone

Best door knobs UK: which listing fits which doors

Mortice door knobs: latch, spindle, backset, spring

Sources

Public UK and manufacturer sources from the research digest, used for this page in October 2026. Prices, stars and review counts are the amazon.co.uk figures in this comparison. None of these knobs is treated as BS 3621, BS 8621 or Secured by Design.

  1. BSI, BS EN 1906:2012 (retrieved October 2026)
  2. HOPPE UK: BS EN 1906 (retrieved October 2026)
  3. Approved Document M, Volume 2 (retrieved October 2026)
  4. Approved Document Q, 2015 (retrieved October 2026)
  5. Guild of Architectural Ironmongers, accessibility guide (2021) (retrieved October 2026)
  6. Secured by Design: doors, front and back (retrieved October 2026)
  7. More Handles, tubular latch guide (retrieved October 2026)
  8. Suffolk Latch Company: door knobs with locks (retrieved October 2026)