Not all hole plugs are made equal and the same applies to drain plugs. Therefore, when charged with the responsibility of purchasing them, particularly in bulk, it helps to have some background knowledge on the subject. Some of the most common uses of hole plugs include: Sealing unused or redundant holes in machinery, equipment, and electrical enclosures; Protecting threads and fasteners from corrosion, rust, and damage Covering holes in furniture, flooring, and walls to provide a smooth and flush finish; Preventing leaks in pipelines and tanks; Closing off access points to prevent the entry of vermin or pests.