The authors first describe the concept of dimensional lumber and the progress of in-grade testing for dimensional lumber in North America.

The similarities and differences of visual grading rules of dimensional lumber between the Chinese and Canadian standards were discussed in this paper.

A research on machine grading rule of dimension lumber;

Evaluation of modulus of elasticity for dimension lumber by three nondestructive techniques;

By the dynamical vibration and static bending test,it is found that the dynamical test method has a good estimation of the elastic properties of dimension lumber.

The relationship between the steel availability and the numbers of steel specs that affects the ship-yard s benefits is studied.