HOLO-KROME 73078 5/16-24 X 5/8" 內六角螺絲 | 六角驅動 | 合金鋼熱處理黑氧化物 (100 顆/包)

The black oxide finish on these screws looks clean and uniform, and they threaded into my jig without any binding. I used about half the box on a tooling setup and not a single one had a burr or rough edge.

The hex socket drive seated perfectly on my Allen wrench with zero wobble, and the thermal black oxide gave them a consistent, clean look across all 100. I used them to hold a jig together on the mill and not a single one stripped or rounded out.

The black oxide finish on these screws looks sharp and holds up well against oil on my shop bench. They seated cleanly into my fixture plate without any binding, and the hex drive grabbed every time. Solid choice for jig work.