In the present study, extension pure shear equipment was specifically designed for the pure shear experiment to obtain the pure shear properties of cupronickel B10 and provided excellent results. The results showed that B10 underwent obvious strain hardening and strain rate strengthening. At a shear strain rate γ ̇ γ ′ ≤ 17,400 ± 100 s−1, the strain rate strengthening played a leading role. A pure shear Johnson–Cook model with a modified term of the strain rate strengthening effect was established following tests. The modified model described the pure shear properties of B10 more precisely. Using the compression Johnson–Cook model for B10, an internal friction factor model based on the ratio τs/εs was established. According to the empirical ratio γ / ε = 3 , the predicted internal friction factor curve for B10 during high-speed cutting was drawn using this model. The internal friction factor was not constant but changed with the strain and increased with the strain rate. The internal friction factor was 0.52 at a strain rate of 12,000 s−1, which was close to the empirical value μ in = 3 / 3 . [ABSTRACT FROM AUTHOR]