براغي رأس كاب 1-8 × 3-1/4" | محرك سداسي | حبيبات نايلون | خيط كامل | سبائك فولاذية بأكسيد حراري أسود (10 / عبوة)

The black oxide finish wiped clean easily and left no residue on my fingers, which surprised me for a fastener this size. Threads cut into my steel plate smoothly with zero binding, and the nylon pellet held firm after a full day of vibration on the mill.

Installed these in a jig I'm building and the hex socket drive made tightening them in tight spots much easier. The black oxide finish seems durable and they threaded smoothly into predrilled holes.

The nylon pellet in the threads is a nice touch—it kept these 3-1/4" screws locked in place on my fixture without any extra thread locker. The black oxide finish feels slick, and all ten came with clean, sharp threads that seated perfectly.