Wilton Vise Jaw Thread Size

[Kiltabar]

I acquired an older Wilton 745 vise for free - the lead screw retaining clip was missing, so I made a new one, and the jaws were missing with the screws broken off flush. I drilled the pilot holes, but I don’t know what the original thread was (1/4-20 or 1/4-28 maybe?). Replacement jaws came with 6 x 1.0 mm screws, which I can do, but I’d rather tap the original thread size. Does anyone know? Thanks.

 

[rklopp]

FWIW, I just refreshed the Craftsman version of a Wilton 1745, and it had 1/4-20 jaw screws. Those screws were rusted solidly in place, but drilled out fairly easily. I did it in the horizontal mill and snuck up on the minor diameter of the screw with incrementally bigger drills until the screw turned into a coil, and I yanked it out. I would do the same with yours. By sneaking up on the minor diameter, the threads in the iron are undamaged, and then you can measure them and see what size they really are.

 

[Kiltabar]

Thanks - that’s about what I did - but I stopped drilling at #12 (0.189) knowing I was safe but still wasn’t able to see the thread. Is it wrong to be this anal about a vise jaw thread?

 

[rklopp]

I would say you don't have to be anal for at least the next seven thousandths! (#9 drill) Keep going incrementally.

 

[EPAIII]

Use a LEFT HAND drill. Soak it with Kroil overnight FIRST.

 

[Kiltabar]

I know the left hand drill trick, but didn’t have one.
I didn’t know the kroil oil trick, but I have it! I use it frequently.
Anyway, mission accomplished. 1/4-20. The most important part - drilling the holes on center- was perfect, so the rest was easy once I knew the thread size.
Thanks guys!