4-BA × 1/4" براغي رأس كبس بمقبس | محرك مقبس سداسي | ملولب بالكامل | فولاذ سبائكي معالجة حرارية بأكسيد أسود (400 / عبوة)

The hex socket drive grips the allen key without any wobble, and the black oxide coating feels properly slick. I’ve used a dozen of them in a precision assembly and every single one threaded cleanly.

I needed some 4-BA fasteners for a jig rebuild and these hex drive screws fit perfectly. The alloy steel feels solid and the threading was clean all the way down the shank.

The black oxide finish on these screws gives them a nice, uniform look, and they seated perfectly flush in my jig without any wobble. Bought a pack for a machinery project and used about half—every single one threaded smoothly without binding.