M8-1.25 X 220mm 소켓 캡 나사 | 육각 소켓 | 부분 나사산 | 클래스 12.9 합금강 열처리 블랙 옥사이드 (50개/팩)

The threads are clean and the thermal black oxide finish looks uniform across all 50 pieces. I used them to bolt down a heavy fixture plate, and the 12.9 alloy steel handled the torque without any flex.

Needed some long bolts for a custom tooling fixture, and these 12.9 alloy screws handle the torque without any flex. The black oxide finish looks clean and feels like it'll resist rust well enough in my shop.

The 220mm length is spot-on for my jig builds, and the black oxide finish wiped clean easily after a quick oil bath. Threads engaged smoothly at the partial thread start, no binding on the first pass.