M30-3.5 X 380mm براغي ذات رأس مقبس سداسي | محرك سداسي المقبس | ملولبة جزئياً | فولاد سبائكي فئة 12.9 مع أكسيد أسود حراري

The black oxide finish on these M30 screws looks quality and seems corrosion-resistant. I used them for a heavy-duty tooling setup, and the hex socket drive made installation straightforward. They feel sturdy and exactly as described.

Installed these on a heavy jig and the hex socket drive took full torque without stripping. The 380mm length was exact to spec and the thermal black oxide finish gives them a nice, uniform look.

The 12.9 grade alloy steel feels seriously tough for my heavy tooling setup. Threads cut cleanly into the tapped hole on my press jig without any binding. Only knock is the black oxide finish seems a bit thin in spots, but for the strength at this size I'm still quite happy.