An Adventure in Leg Vise Rebuilding

Article written and contributed by Tim Suter

Getting it home I promptly tore it down for clean up and closer inspection. This was indeed an old and very interesting vise. It appears to have been made by hand, hammer and anvil, without the use of a mechanical hammer. The screw box eyes were formed by the leg stock (1 1/2" X 1 1/2") being forged out to 5/8 X 3 X 16 inches, folded over at about eight inches, the eye formed around a mandrill and forge welded back into itself, then forged to octagon to round and with the usual upset at the bottom. The jaws themselves are a separate forging, forge welded onto the top of the legs. At the bottom of the movable leg is an offset for the pivot bolt hole. It appears to have been made with two pieces of the 1 1/2" square stock 3 1/2 inches long stacked at the inside bottom of the leg and forge welded together. A possible explanation for the 1 1/2" square stock is that it was a common bar stock size

I put the screw box assembly in my gas forge and brought it up to bright orange to melt the brass, expecting to easily extract the worn and damaged screw thread. Not so, the thread was distorted and tangled and refused to come out easily, so I bumped it on the pavement several times which promptly distorted the tube to a point of no return. Now I had to take it apart to salvage the thrust rings, end plug and no turn lugs. This was more difficult than you might think. It seems to me that things that have been together a long time like it that way.

To make the screw helix, I formed that with 3/16" key stock, the dimensions came out compatible with the screw thread depth and 1 1/2" ID pipe for the barrel. I wrapped the key stock into the screw threads, carefully correcting a twist that wanted to develop as I progressed. This was done cold so the helix could spring open a bit to have a more comfortable clearance with the screw. Six foot of key stock yielded about eight inches of helix. Next I made a sleeve of .040" brass that fit snugly around the screw helix. (When soldering or brazing remember mothers admonition "cleanliness is next to Godliness") I thoroughly cleaned the inside of the pipe and the brass sleeve, fluxed them with a paste flux and put the thread helix into the sleeve.

I wanted to put the screw into the helix in order to assure a proper thread alignment. The problem would be, how to keep the brass from fluxing onto the screw. This was solved by coating the screw liberally with high temp 1500° spray paint. I cured the paint according to the instructions and ran the screw into the helix. Then the brass sleeve, helix and screw were coaxed into the pipe as a unit, it was a very snug fit. The four foot length of pipe was not cut as I wanted a good handle on a piece that would, otherwise, be awkward to handle with tongs. The eight inch depth of my forge was just right for the heat zone I needed, with the screw excess through the back door. The piece was put in the forge, the forge lit and brought up to heat along with the piece. As it came up to heat I could observe,

Now for the moment of truth, would the screw be free? I tried to turn it with a bar, no movement, don’t panic! I bumped the bar with a hammer, again, again, a barely perceptible movement, again, more movement, a sigh of relief. Continued teasing and the screw was out. After fully cooling the screw was teased in and out several times and as the flux residue was broken up the action became increasingly smoother. The pipe was cut to length and the end forged over and into the groove of the end plug, using a torch and localized heat. A short piece of 2" ID tail pipe was forced over the 1 1/2" pipe to form the bell, forged over and gas welded to the 1 1/2' then planished to a nice transition into the contour of the end plug. The thrust rings and no turn lugs were brazed individually to the assembly with the screw back in place to assure preserving thread alignment.

I used a 3/4 X eighteen inch piece of 5160 for the new screw handle. A band of 1/4" X 1/2" was arc welded with a generous fillet at both sides then forged into a suitable ball at each end. The purest could do this in his forge by making a half round with 1/4" X 1" in a swage for the bands. Some jaw mis-alignment was corrected with heat and hammer work at the hinge lugs. The jaw spring of course was no challenge to make.