I got 1000's of these. Boxes of them. 

Two different sizes. #14's and #15's.

The tail is a very fine spring.

I googled my heart out... No luck...

 

 

Maybe a retention spring for something lightweight because with the slit in what appears to be a plastic ring could not hold much weight. Must also apparently be held in position by a set screw or similar device. Now as to use I notice it says glass but in 50 years in retail have never seen anything like it.

 

Now the word PITON means spike or wedge used for mountain climbing, don't think so.But here is some fun stuff more meanings:

What does piton mean in French?

English Translation

 

piton

More meanings for piton

piton noun

 

piton

peg noun

 

cheville, piquet, patère, fiche, excuse

bolt noun

 

boulon, verrou, pêne, culasse mobile, rouleau

Thermostat spring?  Glass part would be an insulator....

No idea what they are, but I'll  bet I could use them for stand-offs for an electric fence wire.

3 hours ago, Fred W. Hargis Jr said:

stand-offs

I don't think that would work.

The springs are very light and soft.

The eye or hole does look to be made of glass.

 

 Seems to me that I may have seen these or something similar in a baking facility. A row of these would be suspended above the conveyor belt that carried fresh baked hamburger buns heading to the cooling area and then to packing. When the pans dumped the buns on to the conveyor some would pile on top of each other and as the buns passed under the springs this was a way to keep them in a single layer.  May not be the correct answer but they look familiar.

Showed them to my brother today. 

He thinks they was used to take slack out 

of sewing thread when used in a knitter.