HOLO-KROME 73090 براغي رأس كبس 5/16-24 × 1-3/4" | محرك سداسي | سبيكة فولاذ معالجة حرارياً باللون الأسود (100 / عبوة)

Had to replace some worn bolts on a milling machine fixture, and these fit the socket perfectly without any binding. The black oxide finish looks solid and should resist rust way better than the old zinc-plated ones I had before.

Used these on a new jig for a production run and the black oxide finish held up perfectly against coolant splashes. The hex drive seated cleanly with no stripping, and the alloy steel threads cut smoothly into mild steel.

Got these for a fixture rebuild and the black oxide finish looks great and seems durable. The hex drive seated cleanly in the countersink without any stripping, which I've had trouble with on cheaper cap screws. Perfect for precision assemblies.