براغي ذات رأس أسطواني مجوف M30-3.5 × 120 مم | محرك سداسي | ملولب جزئيًا | فولاذ سبائكي فئة 12.9 مؤكسد أسود حراريًا (5 قطع/عبوة)

The threads on these M30s are cut clean and the black oxide finish looks evenly applied across all five. I’m using them to bolt down a heavy jig plate and the partial thread gives just the right grip depth without bottoming out. Solid purchase for the price.

Pulling these 12.9 alloy steel screws out of the package, the thermal black oxide finish looks much more durable than the plain steel ones I've been using. They threaded smoothly into my jig without any binding at all.

I had to replace some worn-out bolts on a heavy jig, and these M30 screws fit perfectly with their 3.5 pitch. The black oxide coating on the alloy steel seems durable, and the hex drive made installation straightforward.