Simbi yemugero itambo refu yesimbi ine groove chikamu.Iyo ndeye carbon structural simbi inoshandiswa mukuvaka uye muchina.Icho chikamu chesimbi chine chakaoma chemuchinjikwa uye chikamu chayo chimiro chimiro che groove.Channel simbi inonyanya kushandiswa mukuvaka dhizaini, keteni madziro einjiniya, michina michina uye kugadzira mota.