A 5/16 bolt is stronger than a 1/4 bolt, but as a track hold down, either is strong enough. I don't see anyone using torque busting force to tighten.

 

A 5/16 bolt is stronger than a 1/4 bolt, but as a track hold down, either is strong enough. I don t see anyone using torque busting force to tighten.

- MrRon

+1
But what are you doing that you think you need that kind of torque?

 

Doing nothing but I am unclear on why one vendor chooses one size while the other uses the other
I think the 20 is a less coarse thread and if you need to adjust it allow finer adjustments

 

1/4-20 Vs 5/16-18 doesn't change the tightening torque all that much. It's probably a choice by the manufacturer to avoid having a product too similar to another's.

 

Personally, I would go with 1/4"-20 is the more common used in jigs and fixtures, so that is what I would go with. I always have some of that size around so it I drop a nut or bolt, I can probably fix things without a trip to the store.

 

Two questions. Aren't there some tracks that can use either? And even if you have track that takes 5/16 bolts, can't you still use 1/4" in them too, possibly with the use of a washer?

 

Lots of T-track will use either 5/16 t-bolts, 1/4 t-bolts or 1/4 hex head bolts.

 

I think the T tracks you get from Rockler uses either one. More than anything, I think it's just personal preference.

 

From my experience, most things in woodworking are in 1/4-20. I decided to stick with that. It makes life easier, since you will only ever have to have one driver and one wrench for your screws and bolts. Well, maybe a couple of drivers, if you also use flat head 1/4-20 screws and occasionally larger nuts.

BTW: That's one thing I really like about ShopSmith. They chose to use pretty much only one size of hex driver for all adjustments on every tool they made (with very few exceptions).

Personally, I hate looking for the right wrenches and drivers… it really pays off to stick with one size.

 

Your original premise is mistaken. Lee Valley is not at all "entrenched" with 5/16. If you look on their site, you will see more options for 1/4" than for 5/16". It's your choice.