The woodworker’s workbench is more than just a work surface; properly made it’s an entire clamping system to hold boards you’re working. Most workbenches have two vises built into them; a side vise, which might be a leg vise and an end vise. The actual size and capacity of these vises will depend on the quality of the workbench itself.
woodworking vises always mount flush with the top of the bench, allowing the vise to be used in conjunction with bench dogs. But just what are these “dogs?”
A bench dog is a clamp end, which is inserted into a hole in the workbench top. It is used in conjunction with a tab that slides up and down out of the vise, which is referred to as the vise’s dog. That dog comes with the vise, but bench dogs come separately. You can either buy bench dogs or make your own.
However, some woodworking vises don’t have built-in bench dogs, especially ones with wood jaws and metal hardware. In those cases, there is a hole in the wood jaw, matching the holes drilled into the workbench top, allowing the insertion of the same kind of bench dogs into the vise, as well as the bench top.
Not all bench dogs are created equal. Commercial ones are made of plastic, aluminum or steel. Of course, the material affects the overall strength of the dog and how tight the wood can be clamped. They typically have a round stem, usually about 2 ½” long, with a square or squared off upper portion. The stem sets into a hole in the surface of the workbench, while the square upper portion is the clamping part that grips the wood. Most have a smooth face or one with minimal texture, so as to not mar the workpiece being clamped.
Bench dogs are inserted into either 3/4” or 1” holes in the surface of the workbench or in the front “apron” edge, depending on how they are needed at the time. They are not a permanent fixture on the bench; but rather, used when needed, moving them from one location to another, in order to fit the needs of the moment. It is important that the size of bench dogs bought and the holes in the workbench are the same size, for the bench dogs to work.
These bench dogs are a large part of the reason why woodworking bench tops are so thick. The thickness of the top provides a deep hole for the dog to sit into. This ensures that it won’t tip, wallowing out the hole, when the vise is tightened, putting pressure on the dog. if the bench was only one inch thick, the bench dog would damage the hole, eventually rendering it useless.
Laying Out a Bench for Bench Dogs
Commercially manufactured woodworking benches normally come with the holes for the bench dogs already drilled. There are usually two rows of dog holes, one running perpendicular to each of the bench’s vises. For better quality workbenches, with wide vises, two parallel rows of holes may be provided. In cases where an apron is installed on the workbench, there will be holes for the dogs there as well, but they are used differently in the apron.
However, if you are building your own workbench, you’ll need to drill your own bench dog holes. While you may ultimately decide to add additional bench dog holes in your workbench top, to accommodate holdfasts as well as bench dogs, you’ll want to start out by at least the basic bench dog holes.
The big question here is how far to space the holes apart. The idea is that the bench dogs increase the capacity of your vise; so to ensure that it works well with your specific vise, the spacing is determined by the opening capacity of your vise. So, if you have a vise that has a capacity of 6 ½”, you’ll want to space the bench dog holes out every 5 ½” to 6”, ensuring that you have continual coverage from totally closed, up to the length or width of your workbench.
While some workbenches don’t have bench dog holes the entire length or width, it only makes sense to do it all the way, so as to have the maximum capacity for your bench’s vises. It’s not much more work to add additional holes while you’re drilling them; but it can be extremely difficult to properly align additional holes, to existing ones, if you decide to add them later.
It is your decision whether to use 1” or ¾” holes for your bench dogs, but ¾” are more common. You will want to drill these holes exactly perpendicular to the surface of the workbench, or your bench dogs won’t work properly. For that reason, I made a jig to align my drill, when I drilled the holes in my workbench. You can also attach a portable drill guide to your drill, to help ensure proper alignment.
Additional Holes for Holdfasts
Some people like using holdfasts with their woodworking bench. These are bent, roughly “J” shaped pieces of metal, which go into the hole and then clamp the workpiece down onto the top of the workbench. It’s essentially the same idea as using a bar clamp to attach something to your workbench, but better.
If you use holdfasts with your workbench, then you may want to add some additional holes into your workbench top. While the holdfasts can work with the holes for your bench dogs, assuming that you buy the same diameter bench dogs and holdfasts, the row of holes for your bench dogs may be too far from the edge of your workbench for some operations. You might need some holes that are close to the edge.
Once again, the spacing here depends on the size of your clamp, in this case, the holdfasts. Specifically, we are concerned about the reach of the holdfast, how far it reaches from the hole. This is usually 4” or 6”. Since they are usually used in pairs, you’ll want to space the holes for the holdfasts twice their reach. So, if you have holdfasts with a 4” reach, you’ll space the holes 8” apart and if you have 6” holdfasts, you’ll drill the holes 12” apart.
These holes should be close to the edge, but not so close that they go into your apron. So, depending on the thickness of your apron, you’ll probably want to drill these holes 2” from the edge.
Additional Holes in the Bench Skirt
You may have decided to add a skirt to your bench, to use in conjunction with the side vise, when clamping longboards for planning the edge. In such a case, a bench dog will often be inserted into a hole in the apron, to support the other end of the board.
Since the same bench dogs or holdfasts are used in the apron, as would be used at the top of the bench, the size of these holes will be the same. You will want to make several sets of holes, set at different heights and distances from the front vise of your bench.
Please note that although I have the holes aligned in this diagram, they can be staggered as well, depending on your personal preference.
Making your Own Bench Dogs
While there are a wide variety of bench dogs available on the market, for a wide range of prices, you can also make your own, should you so desire. It can be useful to have more than one set of bench dogs, as you might have something clamped onto one portion of your workbench, then find you need to clamp something elsewhere to work on it. At times like that, it can be convenient to make your own.
I have seen a number of different designs of bench dogs, but probably the simplest is just a piece of dowel rod that has been cut off and had a spring formed into it. The spring is necessary, so as to prevent the bench dog from falling through the hole, before the vise can be tightened. One advantage to a dowel rod bench dog, besides being cheap, is that it won’t mar the workpiece you’re working on, as a metal one might.
To make a bench dog out of a piece of dowel rod, you’ll need a dowel rod that’s the same size as your holes. You want it to fit smoothly into the hole. It should slide up and down and fall through the hole if you let it go, but not wobble from side to side much. If you need to sand down your dowel rod to achieve this, then do so before making the dogs.
Cut the dowel rod to 3” pieces. Then cut a slit into one side of the dowel rod, with a band saw. Round the edges and smooth out any irregularities in the dowel with sandpaper.
The cut you just made will become the spring to hold the bench dog in the hole. To give it spring action, take a thin piece of bare wire and insert it in the slot, near the bottom, so that it forces the tongue you’ve cut into the side of the dowel outwards, turning it into the spring.
You may have to experiment a bit with the thickness of the wire to use in the slot you’ve cut to form the spring. The idea is to have the spring hold the bench dog in place, without being so tight as to make it difficult to remove, when the time comes.
Using Bench Dogs
Bench dogs are used whenever you are trying to clamp a workpiece to your workbench, which is larger than the jaw opening of your vises or when you are holding a long board with your front vise. In order to use it, it’s necessary to first determine which hole to use. So, start by laying the board on the workbench with one end or side aligned with the edge of the vise. Note which hole is the closest to the edge of the board.
Rather than use the hole that you selected, you’ll need to use the adjacent hole, closer to the vise. That way, the travel of the vise jaws will be able to clamp the workpiece between the bench dog and the vise dog. Insert the vise dog in this hole.
If your bench vise has a built-in dog, raise the dog. If it doesn’t then insert another vise dog into the hole in the vise jaws.
Place the workpiece on the bench, up against the bench dog. Tighten the vise until the workpiece is firmly caught between the vise dog and the bench dob, but don’t tighten it enough so that the dogs indent the sides of the workpiece.
Using Holdfasts With the Workbench
Holdfasts are used in cases where a bench dog might not be practical, such as when cutting a tenon into the end of a board or carving the end of the board in some way. Another time when they are useful is if the workpiece has a molded or carved edge, that might become damaged if clamped. They provide a means of clamping a workpiece down to the workbench top, while leaving the edges of the workpiece free.
Holdfasts are almost always used in pairs. So select a location on your workbench top to place the workpiece, where there are two holes available to insert the holdfasts into. You’ll want the holdfasts positioned so that they are not interfering with the part of the board that you will be working on, so be sure to take that into account.
Slide the long leg of the holdfast into a bench dog or holdfast hole in the top of your workbench, allowing the pad on the short leg to sit on the workpiece. Do the same for the other holdfast. When they are positioned properly, strike each on the top firmly, a couple of times, with a mallet to set them. Check the workpiece to verify that it can’t move.
The holdfasts work by spring pressure. They are essentially acting as a spring, locking into place, because one end is held in place by the hole in the workbench and the other is held in place by being pressed onto the surface of the workpiece. This creates spring tension in the metal of the holdfast, which it pushes back against, holding it in place.
When it’s time to remove the workpiece, the holdfasts can be loosened by striking the back of the holdfast, opposite the leg that is clamping down the workpiece. This will cause the spring tension to release and the holdfast to come loose.