What is the maximum height the weld should be left after finishing ground on the running surface?

The maximum height the weld should be left after finishing ground on the running surface is essential for ensuring proper performance and safety of the welded joint in applications such as rail welding. A finishing height in the range of .005 - .007 inches is ideal, as it provides a smooth transition for the surface, minimizing wear on train wheels and reducing the likelihood of interference that can lead to operational issues.

This range allows enough material to maintain the integrity of the weld while not being excessively above the running surface, which could lead to roughness that affects the ride quality and may contribute to wear and tear on adjoining components. Keeping within this specified height also helps maintain the structural stability of the weld joint, ensuring that the connection can withstand the stresses it will encounter during operation.

In contrast, other height ranges either exceed what is deemed acceptable or fall short of maintaining the necessary strength and functionality of the weld. A height outside this optimal range might compromise the structural integrity or create additional maintenance challenges. This is why the .005 - .007 inch range stands out as the correct answer.