M30-3.5 x 320mm 內六角螺絲 | 內六角驅動 | 部分螺紋 | 12.9級合金鋼 熱處理黑色氧化

I needed a heavy-duty fastener for a jig I'm building, and the hex socket drive on these M30s made installation straightforward with a standard hex key. The thermal black oxide finish looks professional and seems like it'll resist corrosion well.

These bolts threaded smoothly into my jig fixture without any binding. The black oxide finish looks more durable than plain steel and the partial threading makes alignment a breeze.

Class 12.9 rating gives me real confidence these will hold up in the jig I’m building—the hex socket drive seated perfectly with no wobble. Partially threaded length was exactly what I needed for a heavy clamp setup.