Hold the saw by its handle with the blade horizontal in front of you. Do not touch or rest the blade on any surface.
Position your ear near the blade and tap your index finger firmly on the metal blade. Listen to hear what kind of sound you hear from the metal blade. A high-quality metal blade will produce a clear ring after you tap it.
Hold the saw handle very firmly in one hand and grasp the tip of the blade with the other hand. Bend the tip of the saw so the blade forms a half circle. The saw blade should bend easily into a round shape.
Release the tip of the saw blade abruptly to see what the blade does. A high-quality saw blade will spring back in a straight line with little reverberation. A lesser-quality saw blade might bounce back and forth several times before settling down in a straight line.