M27-3 X 340mm 六角穴付きボルト | 六角穴ドライブ | 部分ねじ | クラス12.9 合金鋼 熱処理黒色酸化皮膜

The partially threaded design made lining these up in my jig a breeze, and the 12.9 alloy steel feels seriously tough. I've torqued them down hard and the hex socket hasn't stripped a bit. Exactly what I needed for a heavy-duty fixture.

The black oxide finish is so evenly applied that these bolts slide into place without binding, and the 12.9 grade steel gives me total confidence when I torque them down on my press tooling. For 340mm of shaft, they stayed dead straight even under heavy clamping load.

Finally found some properly hardened M27 bolts that don't strip out. The 12.9 grade alloy steel and black oxide finish look serious for my jig build. Threads are clean and the partially threaded section is exactly what I needed for a clamping application.