M22-2.5 X 150mm 소켓 캡 나사 | 육각 소켓 드라이브 | 부분 스레드 | 12.9급 합금강 열처리 블랙 옥사이드 (10개/팩)

The black oxide finish feels properly done—smooth and uniform, no flaking when I torqued them into my jig. The hex socket drive seated perfectly with my Allen key, and the 12.9 alloy steel gives me confidence these won't strip under heavy clamping pressure.

The hex socket drive seated perfectly with my torque wrench, and the thermal black oxide finish has held up without a single smudge during assembly. These feel rock-solid for a class 12.9 bolt, threading smooth into my fixture.

Used these to secure a heavy jig in a drill press and the partially threaded shank made alignment so much easier. The black oxide finish slid right into place without any binding.