1/4-28 × 3/8" براغي ضبط سداسية ذات نقطة كروية محززة | فولاذ سبائكي مطلي بالزنك (250 / عبوة)

The knurled cup point really grips the shaft tightly without marring the surface, exactly what I needed for a stubborn pulley application. These set screws seated perfectly with a standard hex key, and the zinc plating seems durable.

I was worried the hex socket might strip under heavy torque, but these set screws held firm even in a tight spot. The zinc finish makes them easy to see against dark metal, which is a nice bonus for quick adjustments.

The knurled cup point bites nicely into the shaft without slipping, and the zinc plating seems durable enough for repeated adjustments. I used these for a threaded insert application, and the hex drive made tightening them in cramped spots much easier than a regular screw.