Because under normal circumstances, train wheels will not be manufactured separately, but entrusted to a foundry with manufacturing qualifications, so it is a foundry.
Trains, also known as railway trains and green leather cars, refer to vehicles running on railway tracks, which are usually composed of multiple carriages and are one of the important means of transportation for human modernization. As of 202 1, there are two kinds of ordinary speed trains and emus in China. The most important machine in human history, called steam locomotive in the early days, has an independent orbit. Railway trains can be divided into freight cars and passenger cars according to their load capacity, and there are also mixed passenger and freight cars, but they will produce a lot of carbon dioxide and pollute the environment.