براغي ذات رأس مقبس HOLO-KROME 72168 3/8-16 X 2-1/4" | محرك مقبس سداسي | فولاد سبائكي مع أكسيد أسود حراري (50 / عبوة)

Installing these in a jig setup, the hex socket drive grabbed firmly without any cam-out — much better than the standard bolts I'd been using. At 2-1/4 inches, they're the perfect length for my precision assembly work, and the thermal black oxide coating looks clean and resists scuffing nicely.

The black oxide finish on these screws gives them a nice, uniform look, and they seated perfectly in my jig without any binding. I ordered the 50-pack for a few machinery repairs, and the quality feels solid for the price.

The hex socket drive on these 3/8-16 bolts gripped perfectly with my Allen wrench, and the black oxide finish hasn't shown a hint of wear after a few days in my jig setup. Exactly what I needed for a precise tooling assembly.