Q: What’s the deal with the draw tongs I bought, with those wide jaws, big teeth, and hooked handle? I tried to use them for drawing some .35 mm fine wire and gave up in disgust. A regular pair of vise-grips worked a lot better.
A: For very fine wire such as what you’re working with, standard draw tongs are totally unsuited. But, now start with a 3.5 mm square wire (rolling mill production) stock in 18K white gold. Now you’ll be grateful for that strong grip the commercial tongs give you. Same thing if you’re trying to produce, say, 3mm tubing from bent around strip. You need a sturdier grip than standard pliers will give you, and more than the jaw/teeth size, the length of the handles and that hooked over side to one handle, gives you the grip and pull you need. The teeth are large simply because with larger sizes, especially with harder metals, you’d be surprised at the forces acting on the tongs. The jaws need to be that wide and heavy so they don’t bend, and the teeth are larger so they don’t quite so quickly strip out.
Lest you question the degree to which drawtongs can be stressed, I’ll recount how with one pair we had, an innovative one that fit our drawbench (which provides more powerful pull than just hand pulling, of course) the jaw teeth were actual sections of files that had been brazed into the jaws. They worked very well until the time I was pulling down some rather heavy white gold wire, 18K nickel white, about 3mm diameter for a bracelet or some such. I was pulling rather hard on the drawbench crank handle when I heard and felt something snap and release the tension. Seems the force had literally overcome the brazed bond between those sections of file and the body of the tongs. Pulled the teeth right out of one side of the jaws. That required shearing a brazed bond of about one square inch in surface area. Rather a surprise to all of us.
The replacement tongs were a more recent modern Italian pair that weren’t cheap. The jaws of that are still intact, but the teeth on one side of the jaws are pretty much worn flat, mostly from working white gold wire, and I include much smaller sizes, down to about a millimeter or a bit more, after which we usually switch to hand pulling, rather than with the drawbench. But the condition of those jaws in just a few short years attests to the potential forces involved.
For fine wires, you don’t need the special construction of draw tongs. Ordinary pliers can either be used as is, or modified slightly to work better. It depends somewhat on the type of metal you’re drawing into wire. For softer metals, serrated jaws may sometimes tend to cut the wire more than gripping it, while with stiffer metals that may need a bit more tension to pull, serrations may still be useful.
Once I’m down to a size too small for the drawtongs we’ve got (generally somewhere around 6 tenths of a millimeter or so, and this will depend a good deal on your particular draw tongs too) I use ordinary flat-jawed pliers, without serrations. But I use a somewhat coarse Moore’s disk (an adalox disc) to dress the jaw faces flat, and the sanded surface on the jaws provides a very slight bite. The particular pliers I use are not highly hardened, so I also sometimes stand the pliers on their handles, so the jaw tips are pointing up, and slightly opened, and lightly planish the ends of the jaws. This creates a very slight tooth at the front edge of the jaw so it grips a bit better.
Be careful not to overdo it, or the jaws will cut the wire, and take care not to then use these pliers on good sheet metal without first sanding off that tooth, or they’ll leave a nasty mark on the metal. When I get down even smaller, I switch to an even smaller pair of flat-jaw pliers, with narrower jaws that get right close to the dies on my carbide plates, making it easy to grab even the smallest tail of wire sticking through a hole. These very fine pliers are generally not given much front tooth, if at all; just enough so they don’t slip off the wire.
by Peter W. Rowe M.F.A., G.G.