http://www.google.com.hk/search?tbm=isch&q=tool+wear&hl=zh-CN&biw=1554&bih=743&sei=VoRuUbrhB9CykgXj3YGwCAhttp://www.sandvik.coromant.com/zh-cn/knowledge/milling/troubleshooting/tool_wear/Pages/default.aspx