A 4-inch pipe threading machine features a motor for power, a die head system to create threads on pipes, and often an integrated system for cutting, reaming, and oiling. Key characteristics include various threading speeds, the ability to handle different pipe sizes (e.g., 21⁄2"–4" as a separate die head), compatibility with different thread standards like NPT or BSPT, a self-opening die head for quick changes, and durability for heavy-duty use in industrial or construction environments.