Notes on Welding Practice—III

THE materials commonly employed in the fabrication of aircraft structures are confined for the main part to steels of low carbon content (i.e., mild steel, manganese steels of a medium carbon) and chrome‐molybdenum steels. The content of carbon steels that are weldable cannot be exactly laid down, since the amount which can be contended with by the oxy‐acetylene process may rise to as much as 0.8 per cent, although this does not occur in the examples given here where only steels within the region of 0.3 per cent carbon exists.