I am able to offer heat treating of carbon steel blades for those who don't have the facility to do this part themselves. The process is performed in a digitally controlled kiln to enable accuracy. Steels include O1, 1095, 80CRV2, 52100 but feel free to enquire about others. Size wise up to a 12" blade, but again if you have bigger then we can chat. Cost is £8 per blade with postage charged at cost on top using whichever service suits you.