wondering what the opinions here are of suminagashi steel with sg2 core. my reason for asking is that I have access to a limited supply of this steel. Over the week end I forged a 225mm gyoto out of it then hardend and tempered it to specs I found online. after finishing the knife I proceeded with my normal cutting test including cutting hemp rope. the rope I use is the hard dark brown stuff not the soft yellow kind. So with the edge thin enough that it would flex over my thumbnail and left with a somewhat course edge that would shave hair I started cutting.
The method uses only about two inches of the edge near the heal and a pull cut. if the edge starts to slide instead of cut or it I have to use more than about twenty pounds of force I consider the edge done and evaluate number of cuts and edge damage.
this knife easily made 200 slicing cuts with relative ease and no rolling or damge observible with naked eye. I continued to 325 cut where the edge seemed to be losing it's aggressive cutting ability. careful feeling of the edge with finger tips showed a slight rolling of the edge but no visible damage. three passes on a ceramic honing rod brought the edge back to hair popping sharp.
the stone I used for this test is a rather course norton fine india stone. I used this edge because I have many hours of experience rope cutting with it and felt it would let me better evaluate the steel than a finer edge where I don't have as much experience. the rope was cut on a piece of red fir 2x8 lumber that not particularly clean bu neither embeded with dirt a grit from laying around the shop.
I'll post pictures of the knife as soon as I get a handle on it.