Stamping parts should be leveled by a leveling machine after punching. When metal sheets or coils are fed into a stamping press, they can become distorted or uneven due to the force of the press. This can cause problems such as warping, bending, or unevenness in the finished parts. To ensure that the stamped parts are of high quality and meet the required specifications, they need to be flattened and leveled after punching.