Not many “outsiders” see my woodworking bench, or even the inside of my garage for that matter. My pitiful little excuse for a workshop notwithstanding, when a “stranger” does happen to get a peek, one of the first questions usually asked is “how does that vise on your bench work?” My workbench happens to have a leg vise, and when viewing a leg vice from a distance it doesn’t necessarily look like it should work, at least not very easily. But in truth, a leg vise is simple to operate, and one of the more versatile and least expensive vises a woodworker can install on a workbench.
Leg vice and its companion, the board jack…
Leg vises look complex but they are not; in fact they are dead simple. Anybody who has ever used a crow bar is familiar with the concept of leverage, and a leg vise is little more than a lever. On a leg vise, the lever in its basic form is a wood or metal dowel inserted in a parallel guide. A parallel guide is a board which is perpendicular to the vise chop that is attached at the bottom with a tenon. The guide is bored with off-set holes and runs along a through-mortise in the leg of the workbench. The dowel is placed in a hole corresponding to the width/thickness of the board which the user is attempting to clamp. As the vice screw closes and contacts the board being clamped, the parallel guide continues into the leg of the bench, the dowel contacts the leg and the chop levers the clamped board fast. This leverage offers a high-level of clamping power.
Parallel guide and the dowel/lever
So what makes a leg vise so versatile?
First thing is its cost. Decent screw hardware for a leg vise can be purchased new for usually under $50. The chop (or clamping face) of a leg vise is usually shop made. As an example, the chop on my vise was made from a 2 x 10 piece of construction lumber. Cost: less than $10.
Secondly, the configuration of the chop adds to the vise’s flexibility. The chop can be made from nearly any wood species (I prefer 1 1/2 to 2 inches thick), and a width of 10 inches or more is not unheard of (mine is 7 inches wide). This extra width allows for incredible clamping power yet the vise itself remains unobtrusive. In fact, a leg vise is one of the few bench vises that I’ve worked with that does not get in the way of the work. They excel at holding boards for joinery tasks such as dovetailing or sawing tenons. And their clamping power allows a woodworker to raise a board higher than with a typical quick release vise, yet still offer stability because the clamping face of the vise runs the length of the workbench leg-the more surface area the clamped board comes in contact with the better. Which leads to the third merit of the leg vise: the screw.
A leg vise easily clamps wider boards…
Or narrow boards…
Typically, bench vises have two screws along with guides which provide clamping power. The width of a clamped board is beholden to the placement of those screws. The wider the placement the better is the general consensus, as it will allow a woodworker to clamp a wider board through the vise without the screws getting in the way. But the price of the wider screws is a vise that takes up more space (and usually costs much more to purchase and/or make). But even wide-set screws don’t necessarily allow a woodworker to work on the edge of a long, wide board. This leads us to merit number four: the screw placement.
The screw of the leg vise on my workbench sits approximately 12 inches below the top of my workbench. What does this mean? With that placement, I can easily work on the edge of a board 16 inches wide yet have nearly the entire face of the board clamped fast to the bench. This offers maximum stability and clamping strength. I know of no other vise that can say the same. Now there is some ambiguity on where exactly to place that screw. I’ve seen recommendations anywhere from 6 inches below the top to more than a foot. I don’t know the correct answer. Perhaps a decent mechanical engineer could tell you what the optimal placement of the screw would be relative to the width and length of the vise chop. I can only say that I’ve never had a problem with the screw placement on my bench.
This open space between the vise screw and the top of the workbench allow wide boards to be clamped easily…
So what are the drawbacks of having a leg vise? They are not necessarily easy to install. The vise on my bench required boring a hole in both the vise chop and the leg of the workbench. It also requires a through mortise on the workbench leg for the parallel guide, a mortise to hold the vise screw guide/hardware, and a mortise in the vise chop itself (the tenon is on the parallel guide). Needless to say, for the vise to work properly it helps a great deal that this joinery (for lack of a better word) is as accurate as possible. During operation, the top of the leg vice chop needs to close before the bottom for it to work properly, and if your joinery isn’t accurate this will not happen.
A leg vise clamps from the top down…
Another drawback is the parallel guide itself. Because the parallel guide is where the dowel (or lever) correspondent to the width of clamped board is placed, the woodworker using the vise will continually need to change the place of that dowel when clamping boards of differing widths. Fortunately, this can be easily worked around by clamping your boards in sequence.
While on the subject of a parallel guide, there are also no hard and fast rules on how long that guide should be. To again use my workbench as an example, the vise on my bench can theoretically clamp a board that is nearly 13 inches thick (this is the last hole on my parallel guide). Since I can’t really imagine ever using a board close to that thickness, or needing to clamp a board 13 inches wide “face-up”, I made my parallel guide just over 14 inches long. This relatively short length improves the balance, and in my opinion also improves its functionality.
Lastly, a leg vise works best on a workbench with legs that are flush to the bench top. If your workbench has an overhang, or offset legs, there are ways around it, but it will make the installation more challenging, though in my opinion the added effort would be worth it.
So who should install a leg vise? If you are like many woodworkers and you use hand tools it is a great choice. As I said, it is one of the most inexpensive joinery vises you will ever find. IF you happen to be constructing a new workbench a leg vise is a ideal because it is far easier to build into a bench than to retrofit it (though that can be done as well-it just takes a bit longer). The best part about a leg vise is that you don’t need to be married to it. Once assembled, almost all of the components of the vise are part of the chop; you need only back it off all the way and it is removed. The screw guide is mortised into the back of the vise leg and does not interfere with anything on the bench itself. And it is just as easily re-installed.
So don’t let the leg vise detractors scare you. Nearly six years ago I installed one on my workbench with almost no tools and very little woodworking experience. It was only a few months ago that I replaced the chop with a wider board and new parallel guide, and those were replaced as much for aesthetic reasons than for anything else. The original chop was still functioning. In fact, if I were building a new workbench today, the one thing I would not change in the least is the leg vise. Without it, my workbench is little more than a fat table.