M6-1 X 175mm 內六角螺絲 | 內六角驅動 | 半牙 | 12.9級合金鋼 熱處理黑氧化 (50顆/包)

Installed these on a heavy-duty jig I’m building, and the black oxide finish resisted scratches better than expected. The hex socket drive seated perfectly with no stripping, even under torque.

The hex socket drive seated the driver perfectly, no wobble or stripped corners even on the longer 175mm length. Threads ran clean through a jig plate and tightened down true. These 12.9s feel solid, and the 50-piece pack covers a lot of builds.

The black oxide finish on these screws held up perfectly against a few scuffs during assembly, and the 175mm length was exactly what I needed for a jig build. They threaded smoothly into pre-tapped holes with no binding.