Joints for a HEAVY Tabletop

      A tough project has a tricky angle: how to fasten the legs to a heavy table when there's no shelf or apron to control racking. A furniture-maker gets advice from colleagues. July 5, 2005

I have a customer who wants me to build a table out of white oak 3" thick. The top is to be 48" wide and 78" long. The customer brought four pieces for legs that are about 4" to 5" in diameter, and wants me to turn them to straight-round and attach them with mortise and tenon joints directly into the top. The customer wants to avoid any other bracing. I was able to let the customer let me thin the wood to 1 1/2" in the center and only leave the full thickness around the outside edges, but I estimate about 220 pounds just for the top. Does anyone have suggestions to make these joints (legs) safe and secure?

Forum Responses
(Cabinet and Millwork Installation Forum)
From contributor R:
I made a table similar to that years ago. I took 3/8 thick steel plates about 8 inches square and drilled and tapped them. I then rabitted them into the top to make them flush. I screwed them into the top using countersunk screws and pl premium construction adhesive. The reason I went with the spin on the legs is because it’s easy to assemble and the screw holes never strip.

I then used the heaviest railbolt I could find in the legs - these just threaded into the plates nice and strong and were removable. My legs were round, but if you use square you’ll probably have to tighten the plate on the leg and then affix the table to obtain the correct attitude.

As far as strength goes, it turned out amazingly strong because of the over-sizing of everything and the thickness of the top, the legs, etc. (Make sure you drill a relief hole for a bolt to go through the plate into the top a short distance).

From contributor T:
The steel idea is excellent. I use a lot of steel to overcome these designs, but if you are not happy with using steel, then definitely build a sub-top or sub-frame to connect all four legs and you should be solid, except for the leg at the floor which is going to need a tenon to keep the leg from getting kicked out.

From the original questioner:
Great suggestion about the steel – it didn’t even cross my mind. I had a design all worked up with a sub-frame, and was trying to figure a way to eliminate the kick out problem with lags or something at the top above where the pivot point would be. I think since the legs do contain the core, I will drill deep and lag the plate on to the leg itself, then put a couple smaller screws into it to keep it from twisting, and attach the assembly to the tabletop.

From contributor T:
If the table is not attached to the floor, then whenever the client tries to move it the legs will rack no matter what kind of screw you use at the top. It would be best to have a full shelf close to the floor, or at least halfway down to stabilize the four legs at the bottom.

From contributor R:
How close to the corners will the legs be? I think the steel plates could still work, just put the leg end in a corner of a square plate. Just to confuse more, how about a long bolt (12") through the top, countersunk, into a center hole in the leg? Meet the end of the bolt with a perpendicular intersecting side bore in the leg to slide in a washer and nut. Tighten it and plug the holes. You could even square the countersinks and plug with an end-grain piece to faux a tenon end.

Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?

Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Furniture

  • KnowledgeBase: Furniture: Custom Furniture

  • KnowledgeBase: Furniture: Furniture Design

    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.

    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2021 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB

  • WOODWEB - the leading resource for professional woodworkers

      Home » Knowledge Base » Knowledge Base Article