How To Loosen Riveted Pivot?

[Crunch]

Hey, all, I'm just a fount of questions this week.

I just bought a caliper on ebay like the one shown below, and the rivet is tight...way TOO tight to use the caliper the way you're supposed to use these kinds of calipers.

Does anyone know how to loosen the rivet so that it's not so hard to pivot the joint? I was thinking that heating the rivet, while keeping the steel that surrounds the rivet cool, would force the steel rivet to be smaller after it expanded and then contracted, but that doesn't seem to have worked (I tried it just now with an O/A torch, but maybe I didn't get it hot enough)...

I tried penetrating oil, working it loose by forcing it back and forth a few hundred times, and nothing seems to work. Please help!

 

[Jim Coke]

Greetings Crunch,

Use a cup and soak the riveted end in the soloution overnight.. Use a small propane torch and apply some heat ., Place the joint on a soft block ( brass) than tap the joint while attempting to open and close.. This will compress the debri at the joint and allow space for movement..  Take your time more than one application might be necessary.. Good luck..

Forge on and make beautiful things

Jim

[SmoothBore]

Heat the Rivet and the first inch-or-so of the Calipers, to a dull red, ... and flex the joint while hot, ... and continue to flex it until it cools, naturally.

 

.

[Bhutton]

I would try some PB Blaster or some kind of penetrating oil overnight.

Before you get it too hot & damage the calipers make sure it's not a threaded button cap screw? 

The correct term for these calipers is hermaphrodite.    (Her maa  fro dite)

[Gazz]

I would not heat them.  Soak in kroil or other penetrating oil and work them.  They should have some amount of tension so that they maintain the desired setting.  To loose is useless.  Adjust them by opening them farther than required and tap one leg against the edge of your bench or whatever to close them to the setting you need.