8172-A-0440 | فواصل مستديرة Amatom #4-40 × 1-3/4 بوصة | ألومنيوم (50/عبوة)

These are the exact right length for my PCB mounting job, and the aluminum is rigid enough that I don't worry about them bending under pressure. The #4-40 threads on every one of the fifty pieces were clean and consistent, so no wasted time re-tapping.

Used a full bag mounting panel spacers in a test jig, and every one threaded cleanly onto #4-40 screws with no binding. The aluminum is lightweight but feels sturdy enough for the job.

The aluminum finish is clean and consistent on every single piece in the pack, which makes spacing my panel mounts look professional. Threading them onto #4-40 screws was smooth without any cross-threading, and the 1-3/4" length gives just the right gap for airflow between boards.