Abstract
Impact bending work was measured for 101 green samples extracted from branches of a Hinoki (Chamaecyparis obtusa) tree with the pendulum type impact tester. The measured work was proportional to the 3rd power of a sample diameter. Seventy-two samples among the lot were broken completely, and the measured work for them was proportional to each cross-sectional area. The result suggested that it was hard for a small branch to be broken in a stand. It was not denied that Hinoki branches would be broken by a strong wind.
