Salt shaker has more holes, and pepper has less because salt is used more abundantly, and pepper used sparingly. Pepper can clog more readily so the holes are larger. A helpful tip. Salt can bind its particles together in humidity, so add some dry instant rice inside the shaker. with pepper it's always better to use a grinder for peppercorns because it won't clog and pepper flavor is spared in a grind as you use type of container.