M20-2.5 X 170mm 圓柱頭螺絲 | 六角驅動 | 部分螺紋 | 12.9級合金鋼熱黑氧化物 (10 / 包)

The black oxide finish on these M20 screws held up perfectly during a heavy clamping setup on my press. They threaded in smoothly and the extra length was exactly what I needed for a thick fixture plate.

I needed these for a jig on my mill, and the 12.9 alloy steel feels incredibly solid. The hex drive seated perfectly, and they threaded in smoothly without any binding.

Used these M20 bolts to build a custom jig and the black oxide finish held up perfectly against chips and coolant. The partially threaded shank gave me just the right grip length without over-tightening. They feel tougher than any 10.9 bolt I've handled before.