HOLO-KROME 42054 براغي تثبيت سداسية برأس مقبس بنقطة كروية محززة 1/2-13 × 5/8 بوصة | فولاذ سبائكي معالج حراريًا بطبقة أكسيد أسود (100 / عبوة)

The knurled cup on these set screws really bit into the shaft without any slipping, and the black oxide finish should help resist rust in my shop. Exactly what I needed for securing a collar.

Used these to lock a pulley onto a keyless shaft and the hex socket drive made tightening in a tight spot way easier than I expected. The black oxide finish looks clean and the knurled cup point held firm even under some vibration. Solid pack of a hundred for the price.

The hex socket drive seated them cleanly in the tapped holes without any stripping, and the thermal black oxide finish has held up well against minor corrosion so far. I've used about half the pack on a couple of shaft clamps and they've stayed locked in place with no wobble.