M42-4.5 x 170mm 內六角螺絲 | 六角驅動 | 部分螺紋 | 等級12.9 合金鋼 熱處理黑色氧化

Another one of those fasteners that just feels solid in hand; the hex socket drive takes a wrench without any wobble. Used these to secure a jig on a heavy-duty press and the class 12.9 alloy steel holds up well.

Threads cut clean and the black oxide finish gives them a solid grip without any oil residue. These M42s seated perfectly in my jig plate, and the 12.9 rating means I don’t second-guess torque specs.

The partially threaded design made installation on my jig fixture much easier than I expected. These screws really hold up under heavy clamping pressure without any sign of stripping.