Continuous Tube -

where $D$ = outer diameter. For coiling, the minimum bend radius without plastic collapse is:

$$\epsilon = \fracD2 R_b$$

$$\sigma_h = \fracP \cdot Rt, \quad \sigma_a = \fracP \cdot R2t$$ continuous tube

$$R_b,min \approx \fracE \cdot t\sigma_y$$ where $D$ = outer diameter

Bending strain: $\epsilon = \fracD2R_b = \frac25.42 \times 1200 = 0.01058$ (1.06%) continuous tube