M27-3 x 190mm 소켓 캡 나사 | 육각 소켓 드라이브 | 부분 나사산 | 클래스 12.9 합금강 열처리 블랙 옥사이드 (5개/팩)

The black oxide finish is exactly what I wanted for the shop—these M27s slid into place without any galling, and the hex socket drive held the wrench firm even at full torque. The partial threading makes them perfect for clamping down on thick flanges without the threads chewing up the work surface.

I needed fasteners for a heavy-duty jig, and the Class 12.9 alloy steel on these feels incredibly solid under torque. The hex socket drive seated perfectly with my driver, no slippage at all. Definitely saved me from stripping a cheaper bolt.

The partially threaded design made these M27 screws a perfect fit for my jig setup, and the black oxide finish seems ready for workshop wear. Tightened them into a heavy tooling frame and they held firm with zero stripping.