by Robert W. LangWe love nothing more than to completely tear apart a tool, project or technique to figure out exactly how it works. Most of the time our efforts are rewarded with enlightenment, but in the case of holdfasts, we’re still a bit in the dark. It seems that making and using a holdfast has as much in common with art or religion as science.
Before the era of metal vises, woodworkers secured work to benches (horizontally and vertically) with holdfasts. Until the 1920s these were so common that if you saw a workbench, you would likely see a holdfast. Little was written about them because they were so common. To explain holdfasts would be akin to explaining shoes. But they eventually fell out of general use as manufacturers added mechanical gizmos to benches such as tail vises and bench dogs.
And as we found out, that’s a real shame.
Using a holdfast for the first time can be an epiphany. A good holdfast drops in a hole in your bench, and with a few light taps secures a workpiece solidly to the bench. As the holdfast’s pad hits your work, the shaft wedges itself in the hole and against your work.
It is one of the quickest, most secure and efficient methods of holding something down, whether you work with hand tools or power tools. A good pair of holdfasts is like having an extra set of super-strong hands. They can be set in a fraction of the time it takes to secure a clamp or tighten a vise, and their use soon becomes second nature. A light rap on the back of the shaft releases the holdfast’s grip on the work.
Not as Simple as it Seems
As simple as the idea is, the execution and engineering involved in making a good holdfast are complex. The angle of the holdfast’s shaft as it sits in the benchtop, as well as the angle between the pad and shaft are key elements. The size of the shaft, the diameter of the hole and the thickness of the benchtop affect these angles. We found that holdfasts with an angle of about 83° between the shaft and pad functioned best.
The type of metal used, and how it is made are also crucial. We found a difference in performance between mass-produced holdfasts (such as the broken one shown above) and those that were hand-forged (the unbroken one above). We tested them side by side, and found only one mass-produced holdfast we could recommend, and that recommendation comes with reservations.
For our tests we prepared samples of workbench tops using yellow pine and hard maple with various-sized holes between 11/16" and 1" to represent different types of benches. With these workbench samples secured in a vise, we tried each holdfast to see how easily and how securely it would seat. We tried securing pieces of varyin...
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