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Screw Attached Nut Question

  • 1.  Screw Attached Nut Question

    Posted 09-16-2021 17:03
    I am repairing a leg on a not-real-old Wurlitzer fetal grand. The owners moved the piano by pushing it - and yup, broke the rear leg off. Two cast iron nuts that the two leg bolts screw into broke in half. Does anyone know what that nut is called (what type)? It is held in with four smaller screws. It fits a 1/2" diameter machine screw. Anyone recommend a good place to look for one?


    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida

  • 2.  RE: Screw Attached Nut Question

    Registered Piano Technician
    Posted 09-16-2021 19:15
    Maybe one of those specialty screw places. Actually I'd call it a plate or a flange.
    Seems like it could be fabbed out of steel plate.
    Could you install a T-nut from the other side?
    Or plug, redrill for wood screws.

    Steven Rosenthal
    Honolulu HI

  • 3.  RE: Screw Attached Nut Question

    Posted 09-16-2021 21:19
    Check with a Fastenal store near you. The picture almost looks like a pipe flange fitting used on the end of a threaded pipe. You might consider using a hefty nut insert with long bolts . Maybe a metal shop can weld them or fabricate something close. Whatever repair is done will have to support the weight

    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC

  • 4.  RE: Screw Attached Nut Question

    Posted 09-16-2021 23:29
    It's probably a Whitworth thread. ½" x 12 tpi. Gotta love them Brits.  Kawai used Whitworth until 1971 and then went to 12 mm x 1.75 tpi.
    You can get the new fasteners from Kawai or I have more than I'll ever use, Just need to know the length of the bolt; 70 mm or 90 mm.
    Square head, hex head or cap screw (hex key).   Replace both, then you'll have the old spare Whitworth parts for the next repair.

    If you have the Moon Dog Grand Piano Tilter, you have the bolts to compare/determine threads.


    Jon Page

  • 5.  RE: Screw Attached Nut Question

    Posted 30 days ago

    Try this place


    there are also other blacksmiths out there that can make parts. 

    Tricia Turner

    Tricia Turner
    Lehi UT

  • 6.  RE: Screw Attached Nut Question

    Registered Piano Technician
    Posted 30 days ago
    McMaster Carr is a good source, Terry.

    Bob Anderson
    Tucson, AZ