براغي رأس أسطواني M20-2.5 × 80 مم | محرك سداسي | خيط جزئي | فولاذ سبائكي فئة 12.9 بأكسيد حراري أسود (25/عبوة)

The black oxide finish on these screws makes them look right at home in my welding jig, and the hex socket drove in cleanly with zero cam-out. They feel incredibly solid for the size.

I used these 12.9 alloy steel screws for a jig build, and the black oxide finish looks great and didn't chip during tightening. The hex socket engaged perfectly with my driver, making installation smooth even into tight spots.

The partially threaded design made installation into my jig plate much easier than fully threaded bolts would have been. This batch of 25 was enough to finish two tooling fixtures, and the black oxide finish looks professional.