My friend Jonathan over at The Alaska Woodworker scored a load of Acme saw filing machines and vises at an auction. They were all in varying states of repair.
The vise clamping lever has a cam that pushes against a round bolt head. The clamping pressure is adjusted by turning the round bolt in or out with a screwdriver from the back side.
This adjusting bolt was missing from one of the vises. Jonathan picked up a hex head bolt that was the correct thread pitch (13/16″?) and I turned it into a round bolt. To make things a little more interesting, he bought a grade 8 bolt. It turned out to be a non-issue.
I chucked the bolt up and faced the the head smooth. Then I switched over to making the head round. This has to be the first time I’ve intentionally rounded a bolt head. It was a bit noisy at first, but it quieted down as the flats began to disappear. I guess that was the bolt’s way of saying it is wrong to round over the head.
I cut a slot in the end of the threaded portion of the bolt to allow the clamping pressure of the vise to be adjusted. Knowing that Jonathan is a purist when it comes to vintage machinery, I briefly considered cutting a #2 Phillips slot just for fun.
And the finished part…