HOLO-KROME 43022 براغي تثبيت ذات رأس مقبس بنقطة كوب مخددة 1/4-28 × 3/8 بوصة | فولاذ سبائكي مع أكسيد أسود حراري (100 / عبوة)

The knurled cup bit into the shaft really nicely, no slipping at all during assembly. The black oxide finish also seems tough enough to resist the shop oil and grime I work around.

Used these to lock a pulley onto a motor shaft and the hex socket drive made seating them in tight spots a breeze. The thermal black oxide finish looks clean and should hold up against corrosion in my shop.

The knurled cup point grips the shaft like a vise—no slipping even after a full day of vibration on the mill. The black oxide finish looks clean and the hex socket drove in smoothly without stripping. Solid pack of 100 for the price.