This SAE Recommended Practice applies to off-road, self-propelled work machines as defined in SAE J1116, Categories 1, 2, 4, and 5. Plugs are extensively used in off-road, self-propelled work machines as defined in SAE J1116. Loss of these plugs, stripping of the threads, or failure to tighten because of difficulty in finding the right tool can result in serious damage and/or increased down time. All the plugs listed are nominal inch sizes pending the development of metric plug standards. The purpose of this document is to standardize and, therefore, minimize the number of sizes and types of drain, fill, and level plugs required. It also establishes types and sizes of pipe thread and straight thread plugs requiring commercially available hand tools for removal and installation. It is not intended to establish dimensions and materials.