An ultrasonic surgical shears includes an ultrasonic surgical blade, a clamping arm operable to open and close toward the blade, and a tissue pad attached to the clamping arm. A method for sealing a blood vessel of a patient includes obtaining an ultrasonic surgical shears and positioning the blood vessel between the blade and the tissue pad. The clamping arm is operated to exert an average coaptation pressure between and including 120 psi and 210 psi. The blade is ultrasonically vibrated to transect and seal the blood vessel.