M6-1 × 190mm براغي رأس كبس | محرك سداسي | جزئي الخيوط | فولاذ سبيكة فئة 12.9 أسود حراري (50/عبوة)

I was worried the black oxide finish would wear off quickly, but these M6 screws handled repeated tightening in my jig without any visible wear. The hex socket drive engages perfectly with my driver, making installation much easier than slotted heads.

I replaced the standard 12.9 cap screws on my press tool with these, and the longer 190mm length let me finally fit that thick spacer plate. The black oxide finish seems more durable than the raw steel hardware I had before.

I used these on a custom jig for my workshop and the 190mm length gave me just enough reach through a thick bracket. The black oxide coating seems durable and hasn't shown any wear after tightening them to spec.