براغي رأس أسطواني 1/4-20 × 1" | محرك سداسي | حبيبة نايلون | ملولبة بالكامل | فولاذ سبائكي بأكسيد أسود حراري (100 / عبوة)

The thermal black oxide finish gives these a nice, consistent color that hasn't chipped or scratched during assembly. I used them for a small jig and the hex socket drive grabbed perfectly every time, no stripped heads.

The nylon pellet in these set screws holds tight against vibration on my mill's tooling fixtures, and the black oxide finish hasn't shown any wear after a dozen uses.

The nylon pellet locking feature is exactly what I needed for a machine tool assembly, and the black oxide finish gives them a nice, uniform look right out of the bag. They threaded smoothly into tapped holes without any binding.