Takeo Yoshizawa

On the Rockwell Hardness Test of a Thin Metal Sheet : Effect of Anvil

Concerning the superficial hardness test of a thin metal sheet, the effects of spot-anvils made of steel or diamond are investigated. As the sheet becomes thinner, the difference between the measured hardness values obtained upon steel anvil and diamond anvil is significant. We can find a limiting ratio between the thickness of specimen and the depth of indentation. When the ratio becomes larger than this value, the effect of anvil is not recognized any more. It is adequate to use the diamond anvil instead of the steel anvil for the stable and reliable hardness test of thin metal sheets.

On the Rockwell hardness

ロックウエル硬度において硬度値と試驗荷重・基準荷重・金剛石壓子の圓錐頂角および先端半徑ならびに鋼球の直徑との基本的關係をまず求め後者の箇々の誤差が硬度値におよぼす影響を明らかにし,さらに現存する硬試驗機規格の内容を檢討し,ならびに市販の試驗機の改善すべき點を述べ,最後に試驗片につき他の押込硬度を測定した結果も加え諸硬度間の關係を從來公にされている關係表と比較檢討し新關係表を作成した。