Что касается шведов (wetterling, gransfors) четкого состава я, когда выбирал, не нашел, но по некоторым следам на форумах выяснилось что:
Gransfors steel does not have a grade number, it is a
proprietary steel made for them.
It is a plain carbon steel very close to 1055 or EN9, for sure 0.55% Carbon.
Америкосы делают кастомные топоры с пластилином (1018) на обухе и 1095 на РК
PS Ответ с сайта gramfors о процессе закалки РК
After the forging and the first step of sharpening the edge, the lower part of the axe head, the blade, is tempered by warming it to 820°C followed by a quick cooling in cold running water. Then the axe head is annealed: kept for 60 minutes in an oven that is 195°C. This relieves the stress in the steel, built up by the forging and tempering processes and gives the bit the desired hardness and toughness. The hardness of the bit is measured, 57 Rockwell C, and enery single head is tested by a smith who, with a big hammer, strikes on the edge’s corners. If the blade does not break the head is good.