7/16-20 X 7/16" 滾花杯點內六角止付螺絲 | 合金鋼 (100顆/包)

The knurled cup point really bites into the shaft—once these are torqued down, there's zero slippage even under vibration. I used them on a heavy jig fixture and every screw held perfectly after a full shift.

The hex socket drive makes torquing these down in a tight spot way easier than I expected, and all 100 pieces threaded cleanly without any burrs or stuck threads. They’re holding firm on a fixture I’ve been adjusting daily for a week now.

I was worried the hex socket might strip under heavy torque, but the alloy steel handles the load perfectly. These set screws lock in place firmly with the cup point tip, even in my vibration-prone machinery jig.