Blade

刀

dāo

(a weapon such as a dagger)

刀片

dāopiàn

(typically sharp-edged working end of a knife or other cutting tool)

刀身

dāoshēn

(typically sharp-edged working end of a knife or other cutting tool)

刃

rèn

(typically sharp-edged working end of a knife or other cutting tool)

葉片 /叶片

yèpiàn

(the flat part of a leaf or petal)