M6-1 X 40mm 소켓 캡 나사 | 접시 머리 육각 소켓 드라이브 | 부분 나사산 | 클래스 12.9 합금강 열처리 블랙 옥사이드 (300개/팩)

These screws seated flush in my jig plate without any burrs, and the black oxide finish looks clean on the assembly table. The 12.9 grade gives me real confidence in their holding strength under load.

The hex socket drive seated perfectly on my Allen key without any wobble, and the partially threaded shaft gave me just the right grip for my jig setup. Packed 300 to a box, so I’ve got plenty left for the next project.

The thermal black oxide finish is holding up better than I expected on these—no rust spots after a few weeks in my tooling setup. The partial threading makes them a good fit for clamping down thicker plates, though I wish the hex socket sat a touch deeper for easier engagement on tight angles.