M6-1 x 55mm 六角穴付きボルト | クラス10.9 スチール イエロージンク | 部分ねじ (200本/パック)

Used these for a custom machine frame I’ve been welding up; the partial threading kept the unthreaded shank seated perfectly in the jig hole. The yellow zinc finish is holding up nicely against occasional grease splashes.

I needed some decent bolts for a heavy equipment build, and the partial threading on these 55mm caps gave me just enough grip without wasting length. The yellow zinc seems pretty durable so far, and they torqued down smoothly with a socket.

Finally a hex head that doesn’t strip on the first torque, and the yellow zinc finish looks clean enough for visible assembly work. The partially threaded shaft gives me just the right grip depth for my machinery mount.