براغي رأس أسطوانية مقاس #4-40 × 1-1/4 بوصة | محرك سداسي | ملولبة جزئيًا | سبائك فولاذية بأكسيد حراري أسود (400/عبوة)

The black oxide finish is holding up perfectly on these socket cap screws during my jig build. They seated cleanly with a hex key and the partial threading adds versatility. Exactly what I needed for precise assemblies.

Threaded the full 1-1/4" length into a tight jig without stripping, and the hex socket drive grabbed cleanly every time. The black oxide finish also shows no wear after a couple of assembly rounds.

I needed a batch for a small jig I was building, and the partially threaded design on these #4-40s made alignment much easier than expected. The hex socket drive bit snugged right in without any wobble—solid feel for the price.