M20-2.5 X 220mm 六角頭螺絲 | Class 10.9 鋼鍍鋅 | 部分螺紋 (10入/包)

The partially threaded section made alignment in the coupling a breeze, and the zinc coating has a nice, even finish that should resist rust well. These 10.9s feel solid for the price, and the threads cut cleanly without any binding.

The hex head sits perfectly in a socket, and the zinc plating has a clean, uniform finish that looks like it’ll hold up well. I’ve torqued them down on a jig and the 10.9 steel feels rock solid, no stripping or flex.

Used these to bolt a heavy-duty jig frame together and the 10.9 grade steel held torque beautifully without stripping. The partial threading made alignment a lot easier than dealing with a fully threaded bolt in a tight spot.