براغي رأس أسطوانية 1/2-16 × 1-3/4 بوصة | رأس مسطح محرك سداسي | ملولب بالكامل | فولاذ سبائكي فئة 12.9 مؤكسد أسود حراري (50/عبوة)

The threading is clean and precise, so they seat flush without any wobble—exactly what I needed for a jig I'm building. These are solidly tough for the price.

The black oxide finish is so uniform on every single screw that even the threads look flawless up close. I’ve torqued them down hard in a precision fixture and none of the 12.9 alloy steel has so much as stripped a socket. These are the kind of fasteners you forget about because they just work.

I used these for a jig build and the 12.9 alloy steel feels noticeably tougher than the standard bolts I've had strip out before. The black oxide coating gave a nice, even finish right out of the package, and they seated cleanly without any wrench slip.