M6-1 X 15mm 소켓 캡 나사 | 육각 소켓 드라이브 | 풀 나사산 | 클래스 12.9 합금강 열처리 블랙 옥사이드 (600 / 팩)

Put together some precision tooling fixtures last weekend, and these M6 caps threaded in smoothly with zero binding or galling. The black oxide finish looks more uniform than bulk fasteners I've used before, and the 12.9 alloy steel feels noticeably harder under the hex wrench.

Used these for a custom jig I was building and the black oxide finish handled the tight tolerances perfectly. The hex socket drive made installation really easy with no cam-out, and all 600 pieces were clean and uniformly threaded.

Packed exactly 600 in the bag, every single one of these M6 screws has a perfectly clean hex socket that my 3mm driver fits snugly into. They’re holding up beautifully in the jig I built, no stripped heads or wobble at all.