firmness

The baker tested the firmness of the bread crust by tapping it with a wooden spoon.

(Chinese) 面包师用木勺敲打面包皮，以测试其坚硬程度。

You should adjust the air pressure in the mattress to achieve your desired level of firmness.

(Chinese) 你应该调节床垫的气压，以达到你想要的硬度水平。