This is a special tip test method, for different grades of steel can be distinguished.

这是一种鼻尖专用的测试法，对于不同标号钢材均可区分。

youdao

This is a special tip test method, for different grades of steel can be distinguished.

这是一种鼻尖专用的测试法，对于不同标号钢材均可区分。

youdao