M6-1 X 55mm 內六角螺絲 | 平頭內六角驅動 | 半牙 | 10.9 級合金鋼熱處理黑化 (200 顆/包)

The black oxide finish on these looks great and held up perfectly while I was torquing them into my fixture plates. Threads ran smooth with no binding, and the 10.9 rating gives me confidence they'll handle the load.

Needed a solid batch for my jig builds and these didn't disappoint—the black oxide finish feels tough and the partial threads seated cleanly into my fixtures. Fifty-five millimeters was exactly the reach I needed, and the hex socket drive took torque without stripping.

The partially threaded design made these perfect for a jig I was building, and the black oxide finish looks clean. They torqued down smoothly without any issues. Exactly what I needed for precision assembly work.