M20-2.5 X 110mm 內六角螺絲 | 平頭內六角驅動 | 部分螺紋 | 12.9級合金鋼熱處理黑氧化 (25/包)

Installed these on a heavy-duty jig and the partial threading grabbed perfectly without any slippage. The black oxide finish looks professional and seems to resist shop grime well. They're solid enough that I'm not worried about them snapping under high torque.

Finally found some M20 socket cap screws that actually fit my jig without needing to ream the holes. The 12.9 alloy steel feels incredibly solid, and the black oxide finish is holding up well against oil and chips in my shop. Exactly what I needed for a heavy-duty fixture.

The hex socket drive on these M20 bolts seats the Allen key securely, which made tightening them in a tight jig frame much easier than slotted heads. The black oxide finish seems consistent across all 25 pieces without any bare spots. Only wish they came with a few washers in the pack for the price.