... Twisting of flexible shaft core: S/Z direction.Specification of flexible shaft core: Φ 2.2 Φ 2.4, Φ 3.2, Φ 3.8 ... , Φ 4, Φ 5, Φ 6, Φ 6.2, &Phi ... ; 8, Φ 9, Φ 10, Φ 12, Φ 14, Φ 16.Application of flexible shaft core: Widely ... : Smooth, highly-elastic and wear-resistant shaft core is guaranteed.