For years now I have searched for the perfect hold-down tool for work at the anvil, but every one that I have tried has one or more shortcomings. The figure-seven style is quick to make and use, but it just doesn’t hold that well and it won’t hold round stock or odd shapes at all. With the spring-style of hold-downs you either have one you can manage to lift one-handed, or one that holds okay, but never both simultaneously. The hold-downs that rely on weights have all been cumbersome and would barely hold stock for careful punching, but any prolonged hammering caused the stock to move. Mostly, the all got in my way somehow, too. What I needed was a hold-down that would securely hold stock of virtually any cross section without letting go just when you want it least. I also needed one that could be operated one-handed and quickly. A hold-down that takes two hands to set, or that requires a bunch of fiddling around while you lose the heat just doesn’t get it in my shop. All the hold-downs I’d ever seen or tried had one or more critical shortcomings. Clearly, a new approach was required.

Since my chief complaint with my previous hold-downs was that they didn’t hold securely enough, it seemed that the logical place to begin designing a new model was the locking mechanism itself. Once a secure locking method was settled on, the rest could be designed around it. I considered, and rejected, all the methods I’d previously seen in use, and also discarded the notion of using either pneumatics or hydraulics, based on difficulty and cost of materials. I wanted something that could be made in the average blacksmith’s shop without requiring machine tools or close tolerances. After throwing out all the impossibles, I was left with just two possibly workable mechanisms: either an over-center lever locking mechanism or a cam-operated mechanism.

The over-center lever lock, exemplified by the Vise-Grip wrench and the DeStaCo clamp, is a highly positive mechanism that can exert great clamping pressure with only reasonable effort by the operator. The only real drawback is that it takes a fair amount of space and adjustment is critical. A lever lock won’t accommodate much change in stock thickness without being re-adjusted. That left me with the cam for my actuator.

A cam can create pressure over a moderate range of rotation and can “lock” if the axis of rotation is stopped at top dead center or a hair past. Fine, but how does that allow for differences in stock thickness? The cam alone can’t do that, but if it is coupled to the clamp jaws by an adjustable coupler it can. The simplest adjust able coupler I could think of is a simple screw thread so that’s what I elected to use.

That solved the questions of what to use to actuate the hold-down and how to adjust it, leaving just two major hurdles to get over. The hold-down should work on many different cross-sections of stock and it should work with most anvils.

Making the hold-down accept various cross sections of stock simply meant making it with as many different styles of clamping feet as there are different shapes of stock. Wait - that means I’m going to need half a dozen different hold-downs, in a small shop that barely has room for my hammers. That simply won’t do, so the hold-down has to be able to adapt. In one of those “Eureka” moments it came to me: the hold-down should have a receiver that would take different arms for the different stock shapes. That one idea pretty much set me free to stop designing and get on with making the tool.