Back of the blade

Kaldeung (칼등) is the back of a blade: the thick part on the side opposite the cutting edge (칼날, kalnal). The dictionary lists 도척 (dojeok) and 도배 (dobae) as words of similar meaning.

In kumdo the term is applied to the bamboo sword, the jukdo (죽도). The jukdo is made of four bamboo slats held together by leather parts: byeonghyeok (병혁, at the grip), junghyeok (중혁, in the middle) and seonhyeok (선혁, at the tip). The cord stretched from the seonhyeok to the byeonghyeok is called deungjul (등줄) and serves as the kaldeung, the side opposite the edge.

• When the jukdo is held for combat, the deungjul always faces up.
• A strike counts when it is made with the side opposite the deungjul, in the striking zone (격자부, gyeokjabu) between the seonhyeok and the junghyeok.
• In the deun-kal (든칼) position, the jukdo is lowered with the deungjul facing down.
• The Korea Kumdo Association manual asks instructors to teach the direction of the edge (칼날) thoroughly when gripping the jukdo.

A kumdo blog notes that the jukdo has no real cutting edge, so the edge/back distinction is a convention of practice.