The one piece of equipment no workshop should ever be without is a bench vise. A vise adds not only a measure of safety, but also versatility. In fact, a good vise is like having an extra pair of hands, especially when you’re working alone. But this ubiquitous chunk of iron or steel can be made even handier when it’s a co-called multi-vise.
Unlike most vises that are designed with specific tasks in mind, a multi-vise is meant to be adaptable to many functions. One way a multi-vise accomplishes this is with a unique set of jaws, as on this Yost MV-5 unit. Rather than having knurled or grooved jaw faces, the MV-5’s are smooth to prevent marring delicate materials, for instance. But its real superpower comes from the four “jaw dogs” that go in the top of the jaws. Here’s how to put these (accented below in yellow for clarity) and its other unique features to work for you.
Expand work capacity
By inserting the four jaw dogs into the holes in the tops of the jaws, the vise goes from a 2.9-inch opening to more than 7 inches. The expanded capacity is great for holding wider pieces of stock, such as this piece of 2” x 8” lumber.
Clamp irregular shapes
Not everything you’ll need to put in your vise is uniformly shaped. The transmission housing, for instance, has numerous bosses and contours (in addition to being rather large). The four free-spinning jaw dogs center on the part to hold it place more securely than two parallel jaws would.
Secure round objects
Holding round work in a typical vise means there are only two points of contact. Depending on how you apply force, such as drilling, the work may spin in the vise without excessive clamping. In this case, the four jaw dogs create a four-point plain to keep the piece level while working. Less force is required to clamp, preventing damage as well.
Clamp from inside out
Sometimes there’s just no way to put a piece in a vise. It’s either too large or doesn’t have a surface that can be clamped. In the case of this motorcycle wheel, we positioned the pins of the jaw dogs in the center bore and opened the vise to clamp it outward. It’s an unusual way to use a vise, but could be just the right solution for sanding or polishing. And it wouldn’t be possible in a standard vise.
Bend metal stock
With two jaw dogs inserted in the center holes, they serve as leverage points for small bending jobs. And sure, you can certainly make single bends in the jaws of a traditional vise. But this arrangement allows for continuous, multi-radius, and multi-directional bends.
Hold work vertically
The problem with clamping round pieces upright in most vises is they want to spin once you start working. The vertical V-channels in the vise faces are optimized to hold round stock and hardware between ½” and 2” in diameter perfectly upright.
Hold work horizontally
The same problem as above holds true for holding round material horizontally. A pair of horizontal V-channels does the same job in the perpendicular orientation. This is especially helpful when drilling into round stock.