Toolmaker’s Vise Repair

Toolmaker's Vises

Discovered that one of my toolmaker’s vises had a defunct screw securing the jaw to the body: one side of the head simply vanished over the years. Hadn’t mattered up until now, but I really wanted the jaw to not ride up when clamping the workpiece and the screw was rather loose.

It’s difficult to tighten a screw with half a slot…

Eventually I figured out that the screw has a 6-40 thread. My Brownells Gunsmith screw assortment (which they no longer offer) has, among others, 6-48 and 8-40 screws in flat, fillister, socket, and round head, but nothing in 6-40.

After exhausting all other possibilities, I looked in the assortment box again and found four round-head crosspoint screws with captive lockwashers that I must have salvaged from some dead piece of gear.

Of course, they turned out to be 6-40. Whew!

Chopped off the lockwasher, added a dab of Loctite, and it fit perfectly. I flipped the sliding plate over, as it appeared somewhat worn, but I’m certain that didn’t make any difference.

The screw must have a flat head (and you can’t flip the plate over) if you mount the vise on a machined V-way, but that’s not anything I’m likely to do. In that event, maybe I’ll just file the top off the screw and be done with it.

3 thoughts on “Toolmaker’s Vise Repair

  1. You’re right, Brownells slotted head kit does not have 6-40 screws. Brownells does have several screw kits that include the fillister and weaver oval head screws in 6-40. Not called a gunsmith screw assortment but Scope Ring and Base Screw Kit – but they are socket head or torx head.

    1. but they are socket head or torx head.

      And if I’d’a had one of those, I’d’a screwed it right in, even without the right head!

      I don’t do a lot of gunsmithing these days, but my collection of Brownell’s assortments comes in surprisingly handy in the shop. I should probably pick up a few more screw assortments, just to have them around, but …

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