The large ones with 3 holes weigh 11.8 gm, the smaller ones 4.2 gm.
Here's a smaller one that is exactly the same size.
Spikes or feet for a tripod, perhaps?
Well done Marty,
I have 6 sets of tripod legs, 2 use these exact fittings. As the wood grain runs up the tripod legs, they add strength, preventing the grain splitting where the spike are fitted. The other sets are inserted use similar but slightly different sizes, one uses straight tubular collars.
My initial guess had been that the larger, heavier, ones might be weight for the corners of dark cloths. However, the 3 screw holes seem to indicate these are also tripod spikes.
The job lot of brass fittings appear to have come from a camera workshop.
They came in this box, now wood worm treated, re-glued, painted and a light coat of Danish oil. This is just a small assortment of the parts.