Two Jaw Puller Crossarm-Where to Buy?

[u118224]

I have an old Bray 2 jaw puller, probably 5-7 ton, and the forcing screw is shot. Unfortunately, it appears the screw is 11/16-18 non acme, so I doubt I'll be able to find another screw. So, I thought I'd see about buying another crossarm with a more common thread but I can't find any. The Bray crossarm is about 4-5 inches long and has bolt holes on each end. The only crossarms I've seen are Proto without bolt holes, plus they're too long.

The other option is to drill and re-tap the Bray crossarm to 3/4, but I haven't seen any fine thread 3/4 taps available, much less a non acme forcing screw.

This is a nice, heavy duty puller. The original screw was about 9" long and the legs are about the same length and look like they were forged.

Any thoughts on how to make this puller work again?

 

[u118224]

Drill and tap to 3/4-10 and get a proto puller screw.

I believe all of Proto's forcing screws are Acme thread, and I don't know of anyone in N MI that taps Acme thread. I'll double check with Proto on Monday.

 

[2oolhound]

Have a look at #1035 here:

http://www.otctools.com/sites/default/files/mechanicalparts.pdf

A thread is an inclined plane and a fine thread means you have to turn it more times to travel the same distance as a coarse or acme. The advantage to this is you don't need as much force to turn it, something that is nice if you are applying 7 tons pressure.

 

[ttpete]

You could go to 3/4-16, but the practical thing to do would be to just get another puller. Quality pullers die for one reason, and that is because nobody cleans and lubricates the screw with a quality synthetic EP grease before each use. Given that, they'd last almost forever.

 

[u118224]

Have a look at #1035 here:

http://www.otctools.com/sites/default/files/mechanicalparts.pdf

A thread is an inclined plane and a fine thread means you have to turn it more times to travel the same distance as a coarse or acme. The advantage to this is you don't need as much force to turn it, something that is nice if you are applying 7 tons pressure.

That definitely looks like what I need. I didn't know anyone still made an 11/16-18 forcing screw. Thanks 2oolhound!