M16-2 x 180mm 內六角螺絲 | 內六角驅動 | 半牙 | 合金鋼 12.9 級熱處理黑色氧化 (10 / 包)

Threads seated cleanly into my jig’s tapped holes without any binding, and the 12.9 hardness gives me real confidence under heavy clamping loads. The thermal black oxide coating also looks far more uniform than the usual cheap stuff, so these’ll be my go-to for tooling builds from now on.

The black oxide finish on these M16-2s looks properly uniform, and the 12.9 alloy steel feels serious in hand—threading them into my jig plate was smooth all the way. Ten per pack is just enough for a small fixture build, and the hex socket drive made torquing them down a breeze with my Allen key.

I needed some high-strength bolts for a jig I'm building and the 12.9 alloy steel is exactly what I was after. These came in a neat pack of ten, and the hex socket drive seated perfectly with my wrench. They're pricey, but for precision work you can't go wrong.