براغي رأس أسطوانية M30-3.5 X 280mm | محرك سداسي | ملولبة جزئياً | فولاذ سبائكي درجة 12.9 أكسيد أسود حراري

These bolts handled the high-torque clamping on our press jig without any sign of stripping, the black oxide finish is tough enough to resist shop oil residue. The 12.9 alloy steel gives them real heft, and the hex socket drive seated perfectly on my torque wrench.

The partially threaded design made installing these into my jig plate much easier, and the black oxide finish looks clean. They're solidly built for a custom press setup I'm working on.

Used these for a heavy-duty tooling fixture and the 12.9 alloy steel held up perfectly under stress. The hex socket drive made tightening into a tight spot much easier than a regular bolt. Satisfied with the finish and the precise threading.