HOLO-KROME 32190 3/8-16 X 2-1/2" カップポイントソケットセットスクリュー | 合金鋼サーマルブラックオキサイド (50 / パック)

I needed these for a shaft clamping job and the black oxide finish held up well against the oil. The cup point seated perfectly without any wiggle.

The hex socket drive is crisp—my Allen wrench seated perfectly without any wobble, and the cup point gripped the shaft tightly once torqued down. Thermal black oxide finish looks clean and should handle some light shop grime without rusting. Solid fasteners for the price.

Finally, a set screw that actually bites—the cup point dug into the shaft without slipping when I torqued it down. The black oxide finish looks clean and the hex socket drove smoothly with no stripped corners.