براغي رأس مقبس M4-0.7 × 40 مم | رأس زر، محرك سداسي | كامل الخيوط | فئة 10.9، فولاذ سبائكي، أكسيد أسود حراري (400 / عبوة)

The threads on these M4 screws are crisp and consistent—every one of the 400 seated perfectly in my aluminum jig without any binding. The black oxide finish feels durable and hasn't shown any wear after tightening several dozen into steel components. Exactly what I needed for precision assembly work

The hex socket drive bites cleanly with a standard Allen key, and the black oxide finish looks sharp on my tooling fixtures. Threads ran smooth through tapped holes without any binding, and all 400 came out of the box free of oil residue.

Installed a batch on a custom jig this morning and the hex sockets grabbed perfectly without stripping. The 40mm length was exactly what I needed for that through-hole application, and they threaded smoothly into tapped steel.