M3-0.5 x 20mm キャップスクリュー | 皿穴付き六角穴付きボルト | 全ねじ | 10.9級合金鋼 熱処理黒色酸化 (600個/袋)

The black oxide finish looks sharp on my precision assembly rigs, and the hex socket drive grips firmly without stripping. All 600 pieces are consistently cleanly threaded, so I’ve had zero duds so far.

For assembling jigs in my workshop, these hex socket screws have consistent threading and the black oxide finish holds up well against minor oil exposure. The class 10.9 strength gives me confidence they won't strip under heavy clamping loads.

I needed a large batch of M3 screws for a robotics project, and these 20mm ones fit perfectly into the jigs I built—the black oxide coating looks professional and the hex drive is consistent across all 600 pieces.