M2-0.4 X 6mm 內六角螺絲 | 圓頭六角驅動 | 全牙 | 10.9級合金鋼熱處理黑氧化（400入/包）

Used a handful of these for a jig I was building, and the black oxide coating held up perfectly against the metal shavings. The hex socket engaged cleanly with no stripping, even at torque.

I needed small screws for a precision jig project, and the hex socket drive made installation using a tiny Allen key much easier than expected. The consistent threading across all 400 pieces saved me from the usual frustration of sorting through mismatched hardware.

The black oxide finish on these M2 screws looks really clean and professional, and the hex drive makes them easy to install in tight spaces. I used them to secure a small jig on my CNC machine, and they held perfectly with no stripping. For the price, getting 400 of these Class 10.9 alloy steel fast