M33-3.5 X 140mm 圓柱頭螺絲 | 六角驅動 | 部分螺紋 | 12.9級合金鋼 熱處理黑氧化物

The black oxide finish on these M33 fasteners looks properly done—uniform and durable, no flaking when I torqued them into the jig. Class 12.9 strength is reassuring for the precision assembly work I’m doing, and the partial threading gives just the right grip length.

The hex socket drive made tightening these into my jig frame much easier than using a standard hex key, and the 12.9 alloy steel feels incredibly solid under heavy load. Exactly what I needed for a precision assembly project.

The black oxide finish on these screws looks great and held up perfectly during my jig assembly. The hex socket drive made installation straightforward with my Allen wrench, and the 140mm length was just right for the heavy clamping I needed.