Anyone Know About Friction Welding? AKA Making a New Vise Screw

[Eddyde]

HI All,

I am in the midst of refurbishing a 50's era Wilton C1 bullet vise, I picked up for cheap. Several years ago when I started the project, I striped the whole thing down and did an initial cleaning. I found the nut was very worn out so I ordered another. At the time, I thought the screw was still serviceable. Then I got sidetracked and the parts sat in a box on the basement floor for a couple of years...

Naturally, it all rusted up a bit so upon restarting the project, it all went into the Evapo-Rust and a got a thorough wire brushing. That 's when I discovered the screw had some serious pitting on the threads. The replacement is $400 bucks so I'm not going that route. I could make a new one but the acme insert, tool holder and a decent steel bar aren't cheap either. So I figure I could just buy a piece of acme threaded rod for $30 bucks and attach it to the existing handle. But how?

I figure it could be friction welded, in fact I think that's how it was made in the first place. I have screwed around with this technique in the past. However, I have never attempted it on steel of this diameter or for a part that really mattered.

Does anyone have any real world experience with friction welding, or a better Idea for attaching the screw to the handle?


Overall its in pretty god shape for being about 70 years old.

I doubt the damage was due to the rusting, the screw was caked with hardened grease and dirt that I miss in the first cleaning.


Though the screw is still serviceable, I fear the pitting will grind away at new nut.

This is where I think they friction welded the screw section to the handle, when it was made.

Any advice will be greatly appreciated.

Thanks for looking.

Eddy

 

[Ulma Doctor]

if you were so inclined, you could bore the handle and thread it to a nominal size (even LH if you were feeling it)
thread the acme thread into the handle. use locktite or a pin to secure the acme thread into the handle

or

bore the handle and weld the acme thread to the handle outer side

i have not done any friction welding, but i saw some videos of axle housing production and stub axles for the front ends of semi- trucks.
apparently one member is held stationary while the rotating member is gradually forced into the stationary work
the friction creates the heat that ultimately welds the parts together

 

[mmcmdl]

We friction weld every day/night here at work . Not on steel but plastic . The doc is right . One piece spins and the other is stationary . Friction builds up heat until the parts eventually weld themselves together . Our plastic takes only 2.8 seconds .

 

[Provincial]

It looks like there is enough room to vee out both sides, fixture it for proper alignment, and TIG weld it with high strength rod. That would give a full-strength joint and would not require expensive equipment to accomplish.

 

[Nutfarmer]

When I replaced the screw on a Columbia vice years ago the easiest way I found was to grind a tool bit out of high speed steel and turn the screw out of one piece of mild steel. Grinding the bit isn't hard and the total cost is way less than the premade threaded rod. The mild steel has held up for years with all sorts of abuse on the farm. Love that vice. How ever you fix the vise it will probably be better than the new ones. Go for it.

 

[Bone Head]

if you were so inclined, you could bore the handle and thread it to a nominal size (even LH if you were feeling it)
thread the acme thread into the handle. use locktite or a pin to secure the acme thread into the handle

or

bore the handle and weld the acme thread to the handle outer side

i have not done any friction welding, but i saw some videos of axle housing production and stub axles for the front ends of semi- trucks.
apparently one member is held stationary while the rotating member is gradually forced into the stationary work
the friction creates the heat that ultimately welds the parts together

His "bore the handle" I think would be preferable. I imagine a problem with the left-hand threads loctited like locking the vice down on a work piece really hard, and the left-hand thread unscrewing itself when you loosen the jaws.
Yes; I tend to always imagine worse possible results.

 

[Eddyde]

You could bore the handle and thread it to a nominal size (even LH if you were feeling it)
thread the acme thread into the handle. use locktite or a pin to secure the acme thread into the handle

I figure I can leave the screw long and try the weld. Then if it doesn't work, I can use the threaded connection as a back-up plan.

It looks like there is enough room to vee out both sides, fixture it for proper alignment, and TIG weld it with high strength rod. That would give a full-strength joint and would not require expensive equipment to accomplish.

Yes that was my first though but my TIG skills are a bit rusty and I don't have a rotary welding fixture so the set up would be as much as for the friction weld. But if the friction approach doesn't work I'll probably try that next.

When I replaced the screw on a Columbia vice years ago the easiest way I found was to grind a tool bit out of high speed steel and turn the screw out of one piece of mild steel. Grinding the bit isn't hard and the total cost is way less than the premade threaded rod. The mild steel has held up for years with all sorts of abuse on the farm. Love that vice. How ever you fix the vise it will probably be better than the new ones. Go for it.

I do know how to grind HSS tools. But I don't have a piece of bar-stock to make the part and by the time I purchase it it would be more than buying the threaded rod. I also want to clear this project quickly as I have many more waiting... LOL

His "bore the handle" I think would be preferable. I imagine a problem with the left-hand threads loctited like locking the vice down on a work piece really hard, and the left-hand thread unscrewing itself when you loosen the jaws.

If I ultimately do the threaded approach; I'd pin the connection with a setscrew parallel to the axis of the main screw, half in the yoke of the handle and half in the main screw, like a keyway.

Thanks all for the great responses so far. Lots to think about!

 

[markba633csi]

Looks like the original was just vee'd out and arc welded by a skilled person, then ground smooth
I would re-make the screw from scratch and pin it into the old handle- use good steel like 4130 and
use your government issue FBI South Bend!

 

[great white]

TIG.

Done.

 

[RJSakowski]

From what I have seen concerning friction welding, the chuck holding the stationary part has to be able to instantly release the stationary part when the weld is accomplished. It also takes a good sized motor to be able to generate enough frictional heat to reach welding temperatures.