HOLO-KROME 32150 5/16-18 × 3/4 بوصة براغي تثبيت سداسية بنقطة كوب | سبائك فولاذية مؤكسدة حرارياً سوداء (100 / عبوة)

I needed to lock a sprocket onto a shaft and these cup point screws grabbed tight without any slipping. The hex socket was crisp and the black oxide coating looks like it'll hold up well.

Had to replace some worn set screws on a milling machine clamp and these holed up perfectly without stripping during tightening. The black oxide coating gave them just enough grip against vibration, and the cup point dug in nicely. Exactly what I needed for the job.

The black oxide finish really helps these set screws resist rust, unlike some cheaper ones I've tried. They bite into the shaft nicely with that cup point, and the hex drive makes installation a breeze.