What you are describing sounds like a shoulder screw. You might try McMaster-Carr.com to see if you can find a size that works for you. The only one I found without a head is only available in metric threads.
Thread size=10-32, shoulder diameter=?, shoulder length=?
https://www.mcmaster.com/screws/shoulder-screws/
P.S. it looks like for a 10-32 screw the shoulder diameter will be 1/4" from McMaster-Carr.