براغي رأس أسطواني M24-3 X 220mm | محرك سداسي داخلي | ملولبة جزئياً | فئة 12.9 سبيكة فولاذية مؤكسدة سوداء حرارياً (5 / عبوة)

Black oxide finish looks proper and the hex socket drive sits flush without any wobble. Threads run clean on the partially threaded section, and the 12.9 alloy steel feels sturdier than the 10.9s I've used before. These are holding up fine in a tooling fixture I put together.

Installed these into a heavy jig for a production run, and the 12.9 hardness held up without any thread stripping. The black oxide finish is a nice bonus, saved me a step of adding a coating.

The black oxide finish on these M24-3 socket cap screws looks great and seems like it’ll resist rust well in my jig setup. The hex socket drive made installation smooth with my allen key, and the 12.9 alloy steel feels incredibly sturdy for the price. Exactly what I needed for a heavy-duty machinery