براغي ذات رأس أسطواني HOLO-KROME 720003810 مقاس 1-8 × 3-3/4 بوصة | محرك سداسي داخلي | فولاذ سبائكي مؤكسد أسود حراريًا (10 / عبوة)

Needed a longer 3-3/4" bolt for a jig I was building and these socket caps fit perfectly. The hex drive seated cleanly without stripping, and the black oxide coating looks like it’ll hold up well against chips and coolant.

These are the first black oxide screws I've bought where the finish actually looks uniform across all ten pieces, no bare spots or odd streaks. They threaded cleanly into my jig fixture and held torque without any galling on the hex socket.

After fighting with cheaper screws that kept stripping, these socket cap screws threaded smoothly without any binding. The black oxide finish looks clean on my jig setup.