D4400 pistons donate to the cause

I had an emergency home project that required making some solid aluminum collars. Couldn't buy aluminum stock locally and no lead time to mail order it. I searched thru my scap pile and found some old RD4/D4400 pistons. Used a hole saw to cut plugs out of the top. On one piston I veered toward the edge to take a closer look at the two piece threaded top design.

[attachment=7074]IM003237 (Large).jpg[/attachment]

Kent, I am intruiged by what type of handy homeowner project would require such unique and costly items be sacrificed. Unless embarrassment is an issue, do tell... 👋

The pistons were in bad shape: from stuck engine, rings stuck, tops pitted, skirts scored, etc. I have more premium pistons like these in the scrap pile, let me know if interested - the price is right. More on the home project later - it was a timing issue - had to have the parts quickly.