M42-4.5 x 100mm 소켓 캡 나사 | 육각 소켓 드라이브 | 풀 나사산 | 12.9급 합금강 열처리 블랙 옥사이드

Needed some serious fasteners for a custom jig build, and these 12.9 grade cap screws haven't budged under heavy load. The hex socket drive engages cleanly, making tightening a breeze even in tight spots.

The black oxide finish looks properly done and even, and the 12.9 grade gives me confidence these will hold up in my jig setup. Threads are clean all the way down the 100mm length, no burs or binding when I drove them in.

Had to replace some worn bolts on a heavy press jig, and these 12.9 alloy screws handled the torque like a dream. The black oxide finish seems durable and the fully threaded shaft gave me plenty of grip.