Forging Process in Farm Smithies (IV)

On the Edge-Angle and Abrasion of Japanese-Hoes

Abstract

The experiments were carried out to prove that, in the case of using a Japanese hoe, it is from the difference of the steel, alloy layer and base metal of the blade edge, that its edge is worn out at a certain angle.
The results were as follows:
1) Blade edge in which Nabehagane and Zenihagane were used as steel usually had alloy layer.
2) In a used Japanese hoe there was a change in the thickness of steel and base metal, and not in the thickness of alloy layer and in edgeangle.
3) As for hardness, Nabehagane was the hardest, Zenihagane was the second, Carbon-tool-steel was the third and base metal was the last. And in alloy layer the upper part was harder. And Nabehagane and Zenihagane became softer after they were crashed, heated, and cooled, and they became harder after they were crashed, heated, melted and cooled.
4) As for thickness of alloy layer, the upper layer was thicker, and it thickened by prolonged heating time.
5) Both Nabehagane and Zenihagane became harder by forging.