How to Fix a Door Knob That Fell Off

Black doorknob hanging loose on open door

The Spruce / Meg MacDonald

Project Overview
  • Working Time: 5 - 10 mins
  • Skill Level: Beginner
  • Estimated Cost: $0 to $5

You walk into a room and notice that the door knob has fallen off. It's a rare departure from everyday reality, but it does happen sometimes. From constant use, mounting bolts can loosen and cause the knob to fall—sometimes at the worst time. If you can find all of the parts on the floor, you'll have the door knob reassembled and working again in just a few minutes.

Why Door Knobs Fall and How to Fix Them

Modern door knobs consist of two door knob assemblies, one on each side of the door. Two mounting bolts connect the assemblies.

When the bolts are removed or fall out, the assemblies separate. One door knob falls down. Sometimes, the door knob on the other side falls out, too.

Fixing a door knob that fell off is just a matter of fitting the two parts back together, then attaching them with the mounting bolts.

How to Open a Door Without a Knob

If the door knob fell off, you might be stuck inside or outside of a room—apparently with no way to open the door. Not to worry. You're not really stuck.

If the outside assembly is still in place, the long, thin spindle will protrude through the door latch. Turning the spindle is the same as turning the door knob. Since grip is a problem, use pliers to turn the spindle. If you don't have pliers, use a clothespin or two keys rubber-banded together.

If no spindle is available to turn, place an item in the latch's square or small rectangular hole. Use a screwdriver, spoon handle, nail file, or key. Rotate to open the latch.

What You'll Need

Equipment / Tools

  • Phillips screwdriver
  • Cordless drill with bit extender (optional)


  • Replacement mounting bolts (if needed)


Materials and tools to fix a door knob that fell off

The Spruce / Meg MacDonald

  1. Gather the Materials

    To reassemble the doorknob, you will need to locate the inside door knob assembly, the outside door knob assembly, and the two long machine bolts (called mounting bolts) that hold them in place.

    Door knob assembly gathered in front of open door

    The Spruce / Meg MacDonald

  2. Identify the Materials and Their Positions

    • Inside Knob: The inside door knob assembly has an attached rosette plate—a round decorative metal escutcheon. The rosette plate has two holes where the mounting bolts will be inserted. The knob may have a lock to lock the door from the inside.
    • Outside Knob: The outside door knob assembly has a long, thin, square-shaped or flat metal piece in the center called a spindle. On either side of the spindle will be two long metal tubes with female threads to receive the mounting bolts.
    • Latch: The latch is the metal piece that runs horizontally through the door knob hole in the door. It should be screwed firmly in place.


    If the latch feels loose, tighten it by turning the two screws on the edge of the door.

    Inside door knob assembly showing metal escutcheon and plate

    The Spruce / Meg MacDonald

  3. Install the Outside Door Knob Assembly

    With the door open, place the outside door knob assembly on the outside of the door. The long spindle should first be inserted through the square or rectangle hole in the latch, followed by the two female-thread tubes which insert in two round holes.

    Outside door knob assembly inserted into door opening

    The Spruce / Meg MacDonald

  4. Install the Inside Door Knob Assembly

    While holding the outside assembly in place by hand, add the inside door knob assembly. The two holes on the inside assembly's rosette plate should match up with the outside assembly's threaded tubes.

    Inside door knob assembly inserted into door opening with rosette plate

    The Spruce / Meg MacDonald

  5. Add the First Mounting Bolt

    Grasp both assemblies with one hand (by reaching your hand over the edge of the door) or have an assistant do this for you. Add one mounting bolt. Screw it in by hand as far as you can before using the screwdriver. Do not drive it all the way in yet.


    Mounting bolts extend far into the door before they meet up with the female threads. It can be difficult to get this first bolt started, so be patient and go slow.

    Inside door knob secured with mounting bolt into door

    The Spruce / Meg MacDonald

  6. Add the Second Mounting Bolt

    Insert the second mounting bolt the same way as the first. Screw it in by hand as far as possible, then stop.

    Second mounting bolt screwed into inside door knob with screwdriver

    The Spruce / Meg MacDonald

  7. Tighten the Both Mounting Bolts

    With the Phillips screwdriver or a cordless drill with a bit extender, tighten both of the mounting bolts until the door knob assemblies are secured to the door.


    The bit extender is necessary to help the drill's wide keyless chuck clear the door knob. If you're using a manual screwdriver, you won't have this problem. The screwdriver's shank is thin enough to clear the knob.

    Cordless drill securing inside door know to open door

    The Spruce / Meg MacDonald

When to Call a Professional

You may need to call a locksmith if you don't have all of the parts available. It can be difficult to identify and locate the correct replacement mounting bolts for the lock assembly.