I have a door with an old-time door knob, pictured below. What is this style of knob hardware called? What are my options for replacing it?

old door knob

  • 1
    Why do you think you need to replace it? Commented Sep 20, 2023 at 1:38
  • 1
    All the front screws are gone. It looks terrible.
    – cbmanica
    Commented Sep 20, 2023 at 2:06
  • 22
    Take the knob and plate off, use paint remover on them, polish up the brass, and go buy 4 new screws. Might need a bit of toothpick and glue to fill the holes if they are stripped out, so they will hold the new screws. Should look spiffy. Extra points if you get the paint off and polish up the edge of the mechanism in the door.
    – Ecnerwal
    Commented Sep 20, 2023 at 3:02
  • 2
    If you live in an old house with beautiful solid doors and want to replace mortice locks with new ones, have some mercy on the house and buy ones that are better than @AloysiusDefenestrate's sample. :) You don't have to go crazy. Just a little nicer. And if you do what Ecnerwal describes above it'll look far better than a $25 replacement.
    – jay613
    Commented Sep 20, 2023 at 15:46
  • 2
    @ErtySeidohl You can lacquer after polishing if that's a concern (and to polish less.) Most older brass (and newer brass not in plumbing service, or even in plumbing service, depending on the LAHJ) has some lead, but odds are excellent that several of the many layers of paint are also white lead. Likewise, you can de-lead the surface of brass following a NASA method with simple household chemicals (go ahead, ask a new question!)
    – Ecnerwal
    Commented Sep 20, 2023 at 17:56

4 Answers 4


It's a Mortise Lock.

So named because of the rectangular mortise in the edge of the door the mechanism fits in, as contrasted with "modern locks" that mostly use intersecting round holes.

You will have a job getting the mechanism out of the hole with ~27 layers of paint over it and its screws. Hopefully it's obvious that you'll need to remove one knob and the shaft (still connected to the other knob) to slide the mechanism out the edge of the door.

Specialist hardware suppliers will have some options. Other hardware stores can probably order one, but may not stock any, unless the housing stock in your area provides enough business in replacing old locks in the old style for them to do so.

  • It was a mortice lock, but it looks like it has been replaced with a latch-only mechanism.
    – Jasen
    Commented Sep 20, 2023 at 3:01
  • 15
    No, the bolt is there, it's just painted into near-oblivion, and presumably the key's been lost.
    – Ecnerwal
    Commented Sep 20, 2023 at 3:05
  • 2
    But you may be able to find a key in an odds-and-ends shop or at a locksmiths--this kind often uses a warded key, just the profile has to fit the keyway, and sometimes even comes by number.
    – Conrado
    Commented Sep 21, 2023 at 11:53

There are many options for repair or replacement of mortise locks. Parts like knobs in all kinds of materials are available from antique dealers or new. Internal parts like springs are available from locksmiths. If you want to replace the whole thing with something more modern that fits in the existing door, you can buy simple modern mortise locks. If you want to replace it with an ornate but new replica, those are available from specialist historical hardware web sites. If you want to replace it with a not-broken identical one, those are available from antique dealers.

  • Are modern mortise locks all the same size, or do I need to do research to find a modern one that will fit here?
    – cbmanica
    Commented Sep 20, 2023 at 2:11
  • 5
    You will need to research to make sure the original cut out and hole for the knob will match up. Those locks are easy to repair, the biggest trick, whether you replace or repair, is getting it out with it being painted in as well as it is. The mechanism inside is simplicity in itself.
    – Jack
    Commented Sep 20, 2023 at 2:24
  • @Jack: Another difficulty may be adapting a keyed lock to provide secure keyed access while meeting fire codes.
    – supercat
    Commented Sep 20, 2023 at 18:13
  • 1
    @cbmanica you almost certainly do not need to replace this lock. I'd guess this lock was installed between 1910 and 1930. Once you clean off the paint (being careful for lead exposure) the lock will probably function as is with only minor maintenance (pop it open and clean it out). All of the locks in my house are from this era and older, and based on their current state of (dis) repair should easily last another century
    – Steve Cox
    Commented Sep 21, 2023 at 14:31

I just remove all the pieces. Cut some filler wood. Add screws and bondo to get the door back solid enough and then install a standard modern normal door knob. I like the dewalt door knob install kit.

door knob install kit

  • not sure why people downvoted. I've repaired this type of door knob quite a few times before and just had them fail again. There is a reason these aren't used anymore. I like to keep the nice solid original doors in the house but this style of hardware just wears out and the replacement hardware isn't made like it once was or it is and is just not great. Swapping out the whole door/jamb and fixing the trim seems like overkill. Bondo / screws and some paint and you are done. Commented Oct 12, 2023 at 23:15
  • Downvoted because (a) it isn't answered the question that was asked, and (2) repaired right these are quite reliable. They went out of use for security reasons, not reliability reasons, and not every door needs security.
    – keshlam
    Commented 5 hours ago

While you certainly can remove/replace that doorknob as others have suggested, IMO the "correct" way to replace that is to replace the whole door. You can buy a pre-hung door from any of the box stores for around $150, a door casing kit for another ~$30. It's not very difficult to replace a door, and certainly easier than trying to bondo over the hole left from that knob.

  • 2
    The existing door and existing latch and doorknob are much better made than any pre-hung door and hardware from a box store.
    – jeguyer
    Commented Sep 21, 2023 at 15:24
  • @jeguyer sure there is that argument, people also argue that a 1930s car is built better than a modern Hyundai but in the real world one is far more practical. If you want to decorate your home with restored antique architecture and fixtures these knobs are very desirable however based on the paint and the fact that OP is looking to replace it I doubt that is the case. Also not everything old is better. There have always been cheap options, and they are still making very high quality doors. You just have to pay for them like you always have.
    – jesse_b
    Commented Sep 21, 2023 at 15:30
  • Also depending on the end goal you have to look at the time investment. Maybe OP just wants a nice looking functional door. They could spend 20 hours stripping the lead paint off this door, rebuilding and polishing the door knob, or they could spend $200 and 2 hours hanging a new door that will look nice and serve the function of a door perfectly fine.
    – jesse_b
    Commented Sep 21, 2023 at 15:34
  • Finally there is no guarantee this is even an antique knob and door. You can buy a knob set that looks identical to that one (minus the paint) off amazon for $25 direct from china right now. For all we know it could be a 5 year old knob and they just like to change paint colors a lot.
    – jesse_b
    Commented Sep 21, 2023 at 15:39

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