Kyek Pa (Breaking Test) should show the precision and power of a technique. If the wooden board breaks, the technique was done with enough precision and power. Kyek Pa is only practised during examination, and sometimes during demonstrations. It is not practised during class, as Taekwon Do is not intended for destruction (even not boards).
Normally boards of pine or spruce (3cm x 30cm x 30cm) will be used, sometimes (ladies handtechnique or youth people) 2 - 2.5 cm thick boards.