Sawhorses are indispensable for a normal household or a shop. You can use them for painting, work piece support, work bench support with a piece of plywood or door, and with a little imagination, they can be used in many other different ways like magic. The folding sawhorses are particularly valuable, as they can be stored with very minimum space, carried in your vehicle, and set up quickly when you need them.
There are many ways to make folding sawhorses, and it’s not the intention to claim that this is the best way, it's just my way of doing it. If somehow there’s a design details that has been seeing somewhere else, that means either the design was inspired by the other fellow designer's creative mind, which is really appreciated, or all good engineers follow the same physics & design principle - simple, functional, most efficient in strength and maximize material usage. I am sure there are some rooms for improvement for this project, please comment with your idea, and we’ll make it better – will try to make another pair in the near future if necessary.
One more thing to take consideration, the sawhorses were not tested to see how much weight that they can hold up, except I only jumped up and down on one of them with my 175lb body, so they can probably hold at least 200lb each without a problem.
I started with some leftover 1x6 (5.5” x 3/4”) from here and there for the legs, and one piece deck board as beams (treated 5.5" x 1") but didn't have enough for 4 beams, so I replaced one of them with just a 1x6. An 8' 1x6 will yield 3 leg pieces with almost nothing to spare if the the final height stays at 29". Using 1x6 because it’s fairly light and reasonably wide, that will give a chance not to use stretchers at the bottom.
The leg pieces are 31 1/8" long to get 29" of sawhorse finish height, based on the calculation that I will show in next page. The regular sawhorses are 30" high, a few reasons to not go for 30”,
We as regular person normally get 8' boards from the home center, they are 96". If we want to have 30" sawhorse height, then the leg stock would be a little over 32" long, with miter and bevel cut on the boards for this application, we will not get 3 leg pieces out of one 8’ board, our goal here is trying to use up the board and create minimum waste.
In case you do need 30" height or more, you can always add another piece (which will also become the sacrificial piece that you can cut into and replace when it's in bad shape), or even a 6" to 8" high torsion box on the top to make the dimension you would like, and make it the torsion box work table if you need. I built a couple of sawhorse extensions for use of my table saw out feed table set up, click the link if you are interested to see a way to increase the sawhorse height without making another set.
Picture is showing the sawhorses been used in my other project, holding a bunch of 2x materials for part of my basement storage shelf units.