You might be right 74. The only size I buy in carbide is 20″. If you switch between different blade lengths frequently it is probably cheaper to have a roll and make your own. And then there’s the trees people put nails in for whatever reasons. They eat chain. Fortunately what I cut is usually good. It isn’t dirty or real ancient from 150 yo farm houses. I’m a little worried about price increases, so I may be buying a few extra soon. I don’t see any reason carbide tips can’t be sharpened by hand with a diamond coated file. Or maybe its to much work. But a machine with a cutter attachment is sold by Stihl. If it doesn’t cost an arm $ leg.