M8-1.25 x 170mm 外六角螺絲 | 10.9級鋼 無處理 | 部分螺紋 (25顆/包)

The partially threaded section grabbed perfectly when I torqued these into an engine mount, and the hex heads held up without stripping under heavy wrenching. Class 10.9 is no joke, you can feel the rigidity when you're seating them. A full box of 25 means I've got spares for the next job, which is

Used these to mount a gearbox to a steel frame and the 10.9 grade held up perfectly under heavy torque. The partial threads made alignment a lot easier than dealing with full threading. Wrench fit was snug with zero rounding.

The partially threaded design was perfect for my jig fixture build, and the hex head made torquing them down with a socket wrench super easy. These 170mm bolts thread smoothly and feel solid, exactly what I needed for a secure machinery mount.