Technical What are they, I have no clue

Pay for shipping and I'll send you a couple.
Gotta post a pic after you use them though.

 

I think I would buy a Geiger Counter...they look an awful lot like nuclear fuel pellets

 

I worked in factories for 45 yrs. we were always having a special/tool/ spacer/bracket/ guide made. I figure its a special piece for a particular job.

 

Valve guide slugs? Really big rollers for really big rollerbearings? Tool for pressing in and out piston pins? The world may never know! Any part number on the tubes?

 

No identification marks other than that C.

 

Are the hardened?
What other tools and auto stuff did you get with them??
Might point us in a direction.

 

Go back to the yard sale and find out the profession of the owner of the house/parts. That may help.

 

Nothing that would be associated with these. It was basically a table with all kinds of stuff on it. I made a box, paid and went.

 

I asked the lady there what they were. She said she's cleaning out her garage.
My guess, since most of the sale was man related, he either died or left. She didn't know and was super cheap on everything.

 

I use something similar when testing machined pieces coming out of a CNC machine. If one fits in the hole the hole is a "go", if the other fits in the hole is a "no go".

 

When i first laid eyes on these many years ago, I thought they looked so cool. So I started collecting them in different sizes. Have many useful applications besides their original purpose.

 

Mine have a hump at the top and the hole doesn't go all the way through. I guess you could use them for a mount for something.

 

Your's might be partially pre-drilled but not fully finished yet. Mine were finished to accommodate mating different diameter HD mxer rods. Most had set-screws. Yeah, I use the stainless variety mostly for quick-mounting pipe on vehicles.

 

With all the end profiles being the same, first thought was a divot punch uses in a turret press.
For counter sinking fasteners in sheet metal.
You would be missing the die portion.

 

I looked at the tall ones with the rib lines on them. I have two in the pic.

There IS threads in those two pieces and they are hollow all the way to the top. The small group is solid except for the hole at the top and the flat bottom.

I did buy two J dewey cleaning rods but they don't seem to work with these.

They are hardened.