Tenon size for 30x50 kitchen table

[sholtobros]

I've been wondering about my decision to use a 3/8 thick tenon on the aprons for a somewhat shaker style cherry kitchen table. The aprons are 7/8 thick by 4 inches (with arched centers) high so there's plenty of room for a thicker tenon. Legs are just under 2 inches square and I was planning for a 1/8 reveal between the apron and leg. This leaves 3/8 of leg material on the outside of the leg mortise. I keep wondering whether I should go up to a 1/2 tenon but would need to increase the reveal to maintain the balance between mortise width and material thickness to the outside of the leg. So the simple question is does a 3/8 tenon seem too lite for a kitchen table? A 1/2 tenon would be moved inward on the leg just a bit and would shorten the length available before the tenons intersect. It seems like more length is much better for glue area on the 3/8 but I just keep wondering what the difference in the wood strength is between a 3/8 and 1/2 tenon. I'm sure either one would function fine at least in the beginning.

One other detail is how large should the haunch be to maintain the leg strength above the mortise. I was somewhat arbitrarily thought 3/4 would be good. Is there a standard practice?

So I'm new to the forum and enjoy reading all the various experiences of everyone and hope to learn more about the fundamental principles in woodworking and furniture design.

Scott

[iSawitFirst]

I think 3/8" is fine if the stretcher is around 4-5 feet in length. Make the tenon as wide as possible to resist shear and make sure its a good fit.

[Pete Bennett]

Normal practice is not to make a tenon thicker than 1/3rd of the total thickness of the piece you are morticing, so a 3/8" tenon is well inside that and certainly should be thick enough for a table apron of the dimensions you quote. Like the man said make it a wide as you can and make it a good fit. I wouldn't worry too much about how much of a haunch you leave. On some very large tables I have often had no haunch at all and simply mitred the tenons to meet in the mortice. It would also be good practice to drawer peg the legs into the mortices. Although on legs as thin as these you would need to be careful. You don't want to split out at the shoulders.

[sholtobros]

Thanks for the responses. Seems like 3/8 is a reasonable tenon thickness. I tend to over think this kind of thing although if the project moved forward faster I'd have less time to question each step repeatedly. Using pegs is a nice idea. Is it typical to offset the pegs slightly to reduce the tendency to split or is more a matter of opinion and visual preference?

-Scott

[Pete Bennett]

Thanks for the responses. Seems like 3/8 is a reasonable tenon thickness. I tend to over think this kind of thing although if the project moved forward faster I'd have less time to question each step repeatedly. Using pegs is a nice idea. Is it typical to offset the pegs slightly to reduce the tendency to split or is more a matter of opinion and visual preference?

-Scott

Normally I'd say its personal preference but, as your legs are not large I'd agree a stagger would be best. However, if you study old master's work when pegs were used much more to pull a joint up tight and not rely on adhesive, they are normally very close to the face edge. I think this has more to do with the timber not being quite as dry as to-day's kiln dried stuff. With the pegs close to the edge any shrinkage would tend to pull the joint even tighter. Having said all that though, they do frequently show signs of splitting. If you're using a 3/8" tenon on less than a two inch square leg I'd go for no greater than a 3/8" peg. either of the same timber as the rest or if you have something harder use that.

All the best, and post some pics.

Pete