HOLO-KROME 69430 M6-1 x 40mm 低頭內六角螺絲 | 內六角驅動 | 合金鋼 熱處理黑色氧化 (100 顆/包)

The thermal black oxide finish on these M6-1 x 40mm screws is holding up great in my jig setup, no rust after weeks of use. They drive smoothly with a hex key, even in tight spots where a regular socket cap wouldn't fit. Exactly what I needed for precision assemblies.

The low head profile on these M6-1 x 40mm screws let me get into a tight spot on a tooling plate where a standard cap wouldn't have cleared. The black oxide finish has a nice, even grip to it, and all one hundred threaded in without a single burr or hiccup.

The black oxide finish is exactly what I needed for a precision fixture—gives them a clean, professional look and they thread smoothly into tapped holes every time. The low head profile let me fit them in a tight spot where a standard cap screw would’ve been too tall.