I don't want to get the standards of hardness very hard, but the naikoshi standard is hrc-67-69.<br>Because the measurement of Vickers hardness changes greatly in the polishing state and measurement skill of the sample, attention is necessary<br>If it is hard, the wear resistance is improved, and the life will be improved, and the life may be short.<br>The difference of hardness is different this time.<br>If you have different life expectancy, you need to ask for quality investigation in Japan<br>Please confirm the problem concretely<br>
正在翻译中..