HOLO-KROME 86044 M8-1.25 X 18mm 套帽螺絲 | 圓頭六角凹槽驅動 | 合金鋼熱處理黑氧化物 (100入/包)

The black oxide finish on these button heads is a nice touch for tooling—they don't rust after sitting in my drawer for weeks. They seat cleanly in a jig I built, and the hex drive grabs without stripping even on a tight torque.

Installed these in a jig plate at work and the black oxide coating held up perfectly against metal shavings. The button head profile sits flush enough for tight clearance areas without sacrificing hex drive engagement.

Finally found the right length for a tight jig assembly — these 18mm button heads sit flush without bottoming out. The black oxide finish looks clean and should resist rust well in my tooling setup.