HOLO-KROME 32138 براغي تثبيت برأس مقبس نقطة كوب مقاس 5/16-18 × 1/4" | سبيكة فولاذ بأكسيد أسود حراري (100 / عبوة)

The cup point bites into the shaft nicely and holds firm, even with just a hand-tightened hex key. These are headless, so they sit flush in the tapped hole, which is exactly what I needed for a clean assembly.

Finally, a set screw where the hex drive actually engages without wobbling. I used a dozen to secure a shaft collar on a prototype jig, and the black oxide finish held up perfectly against the shop oil. These are exactly the quality I’ve been hunting for.

The cup point on these set screws really bites into the shaft without slipping, even with just a few turns. Made quick work of securing a stubborn pulley while resharpening a lawnmower blade.