HOLO-KROME 68036 براغي ذات رأس سداسي مجوف مقاس 5/16-18 × 1 بوصة | رأس منخفض محرك سداسي | فولاذ سبائكي أكسيد أسود حراري (100 / عبوة)

Pulled these out of the pack and the threads are perfectly clean and sharp—no burs at all. They sit flush in my jig fixture with no wobble, exactly what I needed for precision work.

Finally found black oxide screws that actually hold up on my jig fixtures without stripping the hex drive. The low head profile let me fit them into tight clearance spots that standard cap screws wouldn't clear.

Using these low head screws on a tight clearance tooling setup was a breeze since they sit flush in the counterbore. The black oxide finish adds a nice touch of corrosion resistance for shop use.