#4-40 × 3/8" براغي ذات رأس مقبس | محرك سداسي مسطح الرأس | حبيبات نايلون | ملولبة بالكامل | فولاذ سبائكي مؤكسد أسود حراري (100/عبوة)

The nylon pellet in these #4-40 x 3/8" screws is a lifesaver for keeping them snug on my jig fixtures—no more worrying about them backing out mid-run. They’re fully threaded and the black oxide finish looks clean on the tooling, just what I needed for precision assemblies.

The black oxide finish gives them a nice uniform look, and the nylon pellet does keep them from backing out during vibration. Took a star off because a couple screws in the bag had slightly burred threads, though they still seated fine in my jig.

I was pleasantly surprised by how tight these nylon pellet screws hold under vibration—much better than standard machine screws. The black oxide finish seems durable enough for my jig setup. Only wish the package included a few extras.