HOLO-KROME 87221 M16-2 x 70mm 內六角圓頭螺絲 | 平頭六角驅動 | 合金鋼熱處理黑色氧化 (25 / 包裝)

Installed these into a jig for a production run and the 70mm length gave perfect grip without bottoming out. The hex drive seated firmly with no cam-out, and the black oxide finish resisted chips well during repeated adjustments.

The black oxide finish on these looks uniform and held up fine against my wrench, no flaking so far. Threads were clean and seated smoothly into an M16 tapped hole without needing to chase them. Solid heat-treated feel for a jig I’m building, though the 70mm length is a bit specific if you can’t use

Installing these in a precision fixture was a breeze thanks to the hex socket drive, and the thermal black oxide finish looks and feels durable. The M16-2 threads matched perfectly with my tapped holes.