A hydrogen-permeable structure is disclosed, which includes a hydrogen-permeable base in which a fluctuation range of a d value by X-ray analysis measurement is at most 0. An alternate ultrasonic surgical shears has an ultrasonic surgical blade, a clamping arm, and a tissue pad having first and second transverse outer portions and a movable transverse central portion. The cooling fluid pipes in the blow mold are connected to a central cooling fluid supply. The first portion extends from the first intermediate compression chamber and the second portion extends from the second intermediate compression chamber.