Question about breadboard ends tenon thickness

[Joel Daniels]

Hi all, my dining table project has a tabletop that's 1-1/4" thick. I'm planning to put breadboard ends on it and it'll be the first project I've added breadboard ends to. I'm wondering - what's a recommended thickness for the tenons and the mortise walls here?

[Gordon Stump]

I make the tenon 1/3 the thickness of the board.

[Lee Schierer]

For a table the thickness you stated I would make the tenon ~1/2" thick. Make sure you anchor the center of each breadboard and let the fasteners two near the ends of each board ride in slots to allow for seasonal wood movement.

[Stan Calow]

The rule of thumb I learned was 1/3 or as close to it as you can get with your tooling.

Just my opinion: I think you have to consider which way the joint may fail. If some weight is put on the end, you'd want the tenons to break (more fixable) versus the walls of the mortises to break out. Sometimes I think the emphasis on making strong joints should consider the most likely failure mode.

[Joel Daniels]

The rule of thumb I learned was 1/3 or as close to it as you can get with your tooling.

Just my opinion: I think you have to consider which way the joint may fail. If some weight is put on the end, you'd want the tenons to break (more fixable) versus the walls of the mortises to break out. Sometimes I think the emphasis on making strong joints should consider the most likely failure mode.

Yeah, this is actually exactly what I've been curious about. The table top is heavy, so say if someone tried to lift it by the ends to move it, I would want each part of the joint to have enough thickness to support that. We also have young-ish kids who do silly things sometimes, and I wouldn't put it past them to put their full weight on a breadboard end...

Taking Lee's suggestion, would a 1/2" tenon and 3/8" mortise walls be a good amount of thickness to support each part of the joint?

[Jamie Buxton]

Yeah, this is actually exactly what I've been curious about. The table top is heavy, so say if someone tried to lift it by the ends to move it, I would want each part of the joint to have enough thickness to support that. We also have young-ish kids who do silly things sometimes, and I wouldn't put it past them to put their full weight on a breadboard end...

Taking Lee's suggestion, would a 1/2" tenon and 3/8" mortise walls be a good amount of thickness to support each part of the joint?

An additional way to reduce stress on that joint when the kids pick the table up is to make the breadboard end narrower. They get less leverage on the joint. That is, consider making the breadboard end 2-3" wide instead of 6-8".