HOLO-KROME 86004 براغي كاب بمقبس M3-0.5 × 14 مم | رأس زر بمحرك مقبس سداسي | سبائك فولاذية بأكسيد حراري أسود (100 / عبوة)

The black oxide finish is holding up perfectly on my precision assembly jig, even after repeated tightening. These M3 screws thread smoothly into the tapped holes without binding. Exactly what I needed for this tooling setup.

Installed these on a 3D printer build plate carriage and the button head sits flush, no snagging on prints. The black oxide finish looks great and resisted my oily fingers without rusting.

Finally found some proper button heads that don't strip on the first turn—the black oxide finish feels really durable and the threads are clean. Used them to secure a jig I'm building and they fit perfectly in the countersunk holes.