Question

What problem did Japanese sword makers have to resolve when creating a strong katana

Answer 1

Answer:

they needed a sword that was both hard and flexible but would not bend or break

Explanation:

Japanese smiths solved this problem by making the core of the sword with a soft metal that wouldn't break.

A thick mixture of clay and charcoal powder is applied to the blade's upper sides and dull back edge, leaving the sword's primary edge only lightly coated so that it would be flexible.