What is the correct method for using a file on metal?

Applying pressure only on the forward stroke while using a file on metal is the correct method because this technique maximizes the effectiveness of the filing action. During the forward stroke, the file's teeth engage with the metal, removing material through a cutting action. When the file is pulled back, it should not press against the surface because this can dull the teeth or damage the file. The backward stroke is intended to reposition the file for the next forward stroke rather than to cut, making it crucial to keep the pressure during the forward motion only. This technique not only extends the life of the file but also ensures a smoother finish on the metal surface. Proper filing technique is essential for achieving precision and maintaining tool efficiency.