This Tag can be found on monosteel, san mai ,multibar forgings , annealed or hardend to help you pick the right toolsteel for the job. this steel is water hardening and needs the fastest oil quenchend like parks50/rey50 to a hardness after quenching of 67 hrc (temper back to desired hardness) and a highly active and bright Hamon. very suited to forge your self due to the fact it does not air harden at all! so no worries about Forging/annealing this steel at home.