noun
Refers to the sharpened edge of a knife, sword, or similar tool. Can also refer to the blade as a whole.
この包丁は刃がよく切れる。
This kitchen knife has a very sharp blade.
刀の刃が欠けてしまった。
The sword's edge got chipped.
noun
prong; plug blade
Used for the flat metal prongs of an electrical plug. Often in contexts like プラグの刃.
プラグの刃が曲がっていると危険です。
It's dangerous if the prongs of the plug are bent.
刃物 is a general term for bladed tools or cutlery, whereas 刃 is the blade itself.
The kanji 刃 is a pictograph representing a blade with a marked cutting edge. The reading は is native Japanese.