cast iron vise developed a fracture at the base

Cast iron vise developed a fracture at the base

My bench vise developed a fracture at the base. As a result, the vise was not able to function as normal. It could not hold any work piece in place, rendering it useless as a vise. However, some of the parts could still be used. Repairing it by welding would be out of the question because the fractured part was made of cast iron.

Broken cast iron vise component parts. The threaded rod part on the right was still usable.

Broken cast iron vise component parts. The threaded rod part on the right was still usable.

To repair it by welding, it would entail the use of preheating equipment which I don’t have. The welding electrodes for arc welding would also need to be suitable for cast iron. I don’t have this too. Cooling down period after welding could also be critical. So is stress relieving. Considering that I did not have any experience handling this type of welding, I decided to fabricate the broken parts out of mild steel materials and assemble it to work together with the cast iron parts. I am not a professional welder, but fabricating something out of mild steel would be a more workable solution although the finished product might not look nice.

Materials available for fabrication

Materials available for fabrication

I had to fabricate the base for the vise, which would also act as a guide for the moving part. An existing threaded rod nut would also be secured to this.

What I had were two pieces of bent steel bars taken from an old office chair and a few pieces of straight bars. The bent steel bars were ground so that when they were butt welded together, there would be a hole to secure the threaded rod nut of the vise. The bent steel bars were to form the base for the vise.

Sides welded to the base

Sides welded to the base

Steel flat bars were welded to the base to form the side walls. Since these were only available with widths of 40 mm, I butt welded them together to make them wider. Another flat bar was welded at the top. The side and top plates were thus able to guide the existing cast iron horizontal piece.

The clamping face was made out of the original item taken from the old vise. This clamping face and supporting flat bars was also welded in place. Since I did not have any hole tap, I didn’t intend to secure it by screws.

Almost finished bench vise fabrication

Almost finished bench vise fabrication

After the welding had been done, the structure was cut to make it look more presentable. Also any sharp edges were ground off. Any high areas found after trying out the vise was ground away to make the movement as smooth as possible.

Overall, the project was satisfactory. I managed to save a bench vise for future use.