M6-1 x 18mm 內六角螺絲 | 圓頭內六角驅動 | 全牙 | 12.9級合金鋼 熱處理黑色氧化 (600個/包)

The hex socket drive seated perfectly on my Allen key, and every one of the 600 screws came out of the box with a consistent, smooth thread. They’ve held up great in my jig setup so far, no stripping or bending under load.

The black oxide finish on these M6-1 x 18mm screws is even and consistent across the whole lot, and the hex socket drive seats my Allen key snugly with zero wobble. I’ve used them for a few jig builds already and the class 12.9 hardness gives me real confidence they won’t strip during tightening.

I needed a bulk batch of button head hex screws for a custom tooling project, and the thermal black oxide finish on these is holding up well with no chipping. The hex socket drive fits my 3mm key perfectly, and the whole pack was uniformly threaded.