HOLO-KROME 87024 M4-0.7 X 8mm 內六角螺絲 | 平頭內六角驅動 | 合金鋼 熱處理黑氧化物 (100 / 包)

Used a few to secure a small linear actuator mount on my CNC; the flat head sits perfectly flush in the counterbore. The black oxide finish looks clean and held up fine through a long alignment session without any rust or galling.

These bolts fit perfectly into my jig—the flat head sits flush which is exactly what I needed for a clean assembly. The thermal black oxide has a nice matte finish, and the hex drive made installs quick without stripping.

The black oxide finish on these screws made them much easier to work with than plain steel ones, and the flat head sits perfectly flush in my aluminum jig plate. They thread smoothly into M4 tapped holes without any binding.