HOLO-KROME 42045 براغي تثبيت سداسية برأس كوب مخدد 5/16-18 X 3/4" | فولاذ سبائكي مؤكسد أسود حراريًا (100/عبوة)

The hex socket on these drives true without stripping, even at higher torque when clamping a pulley onto a shaft. The black oxide finish gives them a nice, corrosion-resistant look right out of the package. Exactly what I needed for a tight set screw application.

Installed these today on a motor shaft and the hex drive fit snug, no stripping. The black oxide finish seems durable enough to resist a little oil.

The knurled cup point really grabs the shaft surface without slipping, which saved me time aligning a gear. The thermal black oxide finish also feels more durable than plain steel sets I've tried.