Sprue Cutters versus Bolt Cutters

Q: I’m casting bronze jewelry, but my jewelers’ sprue cutters don’t seem to work on my sprues. They hurt my hands, even when I push them against my workbench. Is there a better way to cut this metal? Do I need a powered cutter?

A: While the cutters sold to jewelers as sprue cutters are indeed nice tools, they don’t compare to an actual bolt cutter. Industrial bolt cutters are generally substantially larger, and always have a compound action, so that a large movement of the handles translates to a small movement of the jaws. That results in enormous mechanical advantage, meaning that, unlike the commercially sold jewelers’ sprue cutters, a properly sized bolt cutter does not need much effort from you in order to cut. Keep in mind that they’re intended to cut steel bolts, and a cutter that can slice through a 1/4 inch or larger steel bolt will handle a bronze sprue like child’s play. Beyond resting one handle on your stump or bench, you can also mount it permanently, strapped to a sturdy bench by one handle. That makes it truly a one-hand tool.

The main downside to bolt cutters as opposed to specialized sprue cutters is that bolt cutters are designed with jaws sturdy enough do to their job, which means they’re fairly thick and blunt. So you cannot cut quite as close to your casting as you might with an actual sprue cutter. But since you’re casting bronze, not gold, the slight extra waste shouldn’t be an issue. Also, I’d suggest that rather than getting them from the cheapest possible source, you get the Craftsman brand from Sears. Unlike their power tools, many of their hand tools still carry the traditional Craftsman lifetime warranty, so if that applies as well to their bolt cutters (I don’t know for sure, but believe it would) if you ever break the jaws, they’d simply replace them. And, the quality of their tools, even the ones made these days in China, are better than what you’re likely to find at Harbor Freight or other discount tool importers. If you’re unsure, take one of your bronze sprues and go into Sears and try them out, perhaps with a sales person’s assistance, and you’ll see what I mean about how little force these things require for even heavy-duty cutting, if you get one sized correctly for your sprues.

I’m pretty sure the potential cost savings would make that little shopping trip worthwhile over buying a powered cutter. Note too, that power cutters are also not immune to chipping and breaking cutter jaws, and some of them get pricey to replace. If you do large volumes of such castings, then perhaps the faster power cutters would justify that cost, but at least check out the big bolt cutters first. With the right one, you will not be hurting your hand at all.

by Peter W. Rowe M.F.A., G.G.