The invention discloses a manufacturing method of the scraping tooth knife with double involutes. A main body waited for cutting and hob cutting tool are prepared. The involutes paths cut into the main body and interleaved each other at the given position are set. Minor pressure angle is utilized to produce trochoid with major under-cut. The hob is according to the involutes paths interleaved each other at the given position and trochoid hob main body. Thus, scraping tooth space is formed and can be reached the free effect of the scraping tooth root. Its manufacturing process of the scraping tooth knife has continuity, and can be simplified at one machine. The formed scraping tooth cutting tool has relatively lank cervix, this can improve the strength of the scraping tooth. |