M3-0.5 X 25mm 內六角螺絲 | 平頭內六角驅動 | 半牙 | 12.9級合金鋼 熱處理黑氧化物 (400顆/包)

These flat heads sit flush perfectly in the counterbored holes on my fixture plate, and the hex socket drive makes them easy to tighten without stripping. The 12.9 alloy steel feels rock solid—way tougher than the cheaper screws I used to buy.

Got a full 400-count box for a jig build and every single screw threaded clean without any stripped heads. The black oxide finish looks consistent across the batch and the 12.9 hardness feels properly stiff when torquing down.

The partially threaded design made alignment in my jig way easier than fully threaded screws, and the black oxide finish has a nice matte look that resists smudges. At 400 per pack, I’ve got plenty for future builds without worrying about running out mid-project.