Answer 15: Minimum bend radius is NOT equal to product softness (flexibility). The value of Minimum Bend Radius is defined as the radius (R) when (d’) is multiplied by 95% at room temperature (HAKKO Internal Rule). Thus, Minimum Bend Radius is the index to measure the flatness of the tubing or hose. The more flat the tubing or hose is, the less likely the fluid is to flow.