M14-2 X 45mm 凹頭螺絲 | 六角驅動 | 全螺紋 | 12.9級合金鋼 熱處理黑氧化物 (50件/包)

Put these on a jig fixture that sees daily use, and the hex socket drive makes tightening them in tight spots a breeze. The black oxide finish hasn't shown any wear after a few weeks of assembly and disassembly.

I needed screws that could handle repeated torque on a jig fixture, and the 12.9 alloy steel with black oxide held up perfectly without stripping the hex socket. The fully threaded shank gave me solid grip through the whole joint.

The black oxide finish on these is flawless and uniform across all 50 pieces, which tells me the heat treatment is consistent. Threads are clean and the hex sockets didn't strip when I torqued them into my precision fixture.