براغي تثبيت ذات رأس كوب بنقطة بولي أميد 1/4-28 X 1-1/4" | فولاذ سبائكي (100/عبوة)

The nylon patch is really holding firm once threaded in, and the cup point bites nicely into the metal without stripping. I used these on a new jig build and haven't had a single one back out under vibration.

These are exactly the right thread pitch and length for a jig I'm building—the nylon patch keeps them locked in place under vibration. The hex socket takes an Allen key perfectly, even in a cramped spot.

Installing these on a fixture that sees a lot of adjustments, and the nylon patch is a lifesaver—no more set screws backing out mid-operation. The cup point bites nicely into the shaft without marring it, which I appreciate. Exactly what I needed for the price.