براغي رأس أسطوانية مقاس 5/16-24 × 1-3/8" | محرك سداسي | ملولبة بالكامل | فولاذ سبائكي بطبقة أكسيد أسود حراري (100 / عبوة)

I’ve got these holding together a jig I use daily in the shop, and the thermal black oxide finish hasn’t shown a hint of wear yet. The hex socket drive seated perfectly with my Allen key, no stripping or play. For a hundred pack of alloy steel fasteners, the value’s tough to beat.

The threading on these is clean and uniform, so they seat perfectly without any wobble or cross-threading. The black oxide finish gives them a nice grip feel and they’ve held up well in my jig setup. Exactly what I needed for precision assemblies.

Built a couple of precision fixtures with these, and the black oxide finish on the alloy steel gave them a nice, consistent look that didn't flake off during assembly. They thread cleanly into tapped holes without binding.