8103-A-0440-16 | فواصل سداسية من أماتوم #4-40 × 5/16 بوصة | ألومنيوم (400 / عبوة)

Used these to mount a controller board in a tight enclosure, and the 5/16" length was just right for the job. The aluminum material feels sturdy enough for the weight, and the hex shape made installation simple with a standard wrench.

Had to replace a batch of nylon standoffs that kept stripping, and these #4-40 x 5/16" aluminum ones threaded on clean without any burrs. The 400-count box is a solid deal when you're building a few boards at once, and they hold panels snug without wobble.

The aluminum feels sturdy, and these threaded perfectly into my PCB mounting holes without any binding. A full pack of 400 means I won't run out for a while.