هولو-كروم 72238 براغي رأس أسطوانية 1/2-13 × 2-1/2 بوصة | محرك سداسي | فولاذ سبائكي مؤكسد حراريًا أسود (25/عبوة)

The black oxide finish feels durable and resists marking up my tooling nicely, and the hex drive seated perfectly without any wobble. I used these to rebuild a press fixture, and the 2-1/2" length was exactly what I needed for the stack-up.

Installing these on a jig for a repeat fixture job, the black oxide coating looks more consistent than other batches I've used. The hex socket drive engaged cleanly without any rounding under moderate torque.

These fit perfectly into my mill’s T-slots, and the black oxide finish already resisted a few coolant splashes without any rust. The hex drive seated cleanly with no stripping, which made tightening them in a jig setup feel solid.