براغي رأس أسطواني M42-4.5 × 90 مم | محرك سداسي | ملولبة بالكامل | درجة 12.9 سبيكة فولاذ مؤكسد أسود حراري

The black oxide finish on these screws gives them a serious, professional look, and they threaded into my machinery mounts perfectly without any binding. For a 12.9-grade fastener at this size, the price is hard to beat, and they feel absolutely solid in hand.

I needed heavy-duty fasteners for a jig I’m building, and these class 12.9 alloy steel screws threaded smoothly into the tapped holes without binding. The thermal black oxide coating gives them a consistent, non-reflective finish that looks solid for machinery work.

The black oxide finish on these M42 screws looks great and seems durable. Threaded them into a jig I’m building and they seated perfectly with no wobble. Exactly the strength I needed for heavy machinery work.