M16-1.5 x 80mm 소켓 캡 나사 | 육각 소켓 드라이브 | 부분 나사산 | 12.9급 합금강 열처리 블랙 옥사이드 (25 / 팩)

The black oxide finish looks properly done, no uneven blotches, and the hex socket drive seated perfectly with my Allen key. Threads were clean right out of the bag, no chips or burrs, which made installing them into my jig plate a smooth process. Exactly what I need for heavy tooling work.

Threaded part is just the right length for securing a heavy jig plate without bottoming out, and the black oxide finish looks clean. Torqued to spec without any stripping, these feel solid for the price.

Used these to secure a heavy fixture on my milling table, and the black oxide finish held up fine against minor coolant splashes. The hex socket drive made installation straightforward, though I wish they came with a few extra washers for the price.