45° V-type slot milling cutter head internal and external chamfering cutter head CNC upper and lower inner groove chamfering cutter head SPMT12040845 degrees V type slot milling cutter CNC upper and lower inner groove chamfering cutter SPMT120408 1. The cutterhead processing strictly adheres to the process of heat treatment and then tapping to avoid the deformation problem caused by post heat treatment, and the blade and the blade are closely fitted, and the knife is not bounced with high precision 2. 42CrMoTi alloy steel, quenched and hardened, durable, the surface has been polished, has good