Cheap Vise Issue

[Lorydr]

My Craftsman vise was like $20 used. Over time, maybe from abuse, the screw in & out action has gotten a binding spot at the same point of every turn. Except for the first 1/2" of jaws being apart. That first 1/2" is smooth & easy. Beyond that it gets stiff at the same point. The most I've tried so far, is to add grease in the threads and at any expected friction point. That didn't help.

The vise has been great other than that. Any ideas to try to loosen up the threads?

Actually even the first half inch of opening also has a lesser bit of binding.

 

[Packard V8]

That can describe a bent or stretched screw.

jack vines

 

[GreenIron]

What Jack stated.​

 

[RTM]

That can describe a bent or stretched screw

Would that pass once the bent or stretched portion passed the nut?

Has me wondering about a very “early” bend where it is moving the majority of the threaded in a circle instead of at a point.

 

[Lorydr]

I can understand the bent screw causing binding. So is it "Screwed"?

 

[AreBeeBee]

I assume you've extracted the moveable jaw and visually examined the screw? And not seen anything amiss? How much force you need to move it through the binding spot could give you a clue as to the problem. But I'm with Jack Vines.

 

[seber]

Put a straight edge on the screw and determine the point of bend. Straighten with a soft face hammer.

 

[Lorydr]

Today I pulled the dynamic jaw. Pulled the clip & washer off. The screw had no notable run-out. Without the jaw, the screw went smoothly through the threads, so I looked at other parts. A couple areas needed a bit of filing over burred & dinged spots. I then shot parts with lithium grease and reassembled. Initially it still had some binding at about 2" of opening, but after pushing in a few directions, as I was turning, it then went as smooth as I could possibly ask for. So far my New Year is Happy!