هولو-كروم 33096 براغي رأس سداسية بنقطة كوب 5/16-24 × 1/2 بوصة | فولاذ سبائكي مع أكسيد أسود حراري (100/عبوة)

Used a few of these to secure a pulley on a motor shaft and the hex socket held up perfectly to a pretty snug torque. The black oxide finish seems tough enough to resist rust in a damp garage.

For a small part, these screws have a surprisingly good bite with the cup point. I used them to secure a pulley on a shaft, and the hex socket made installation clean and simple. The black oxide finish looks more premium than I expected for the price.

The cup point bites into the shaft really well and the black oxide finish keeps them from rusting in my humid garage. I used these to lock a pulley onto a motor shaft and they haven't budged under load.