BS means British Standard; this tube is in fact particularly sold in the UK and Northern Europe. The T45 BS is the tube carbon-manganese that was originally used in the details of the fuselage of the Spitfire and Hurricane aircraft.

Since then ti is always used in the aerospace industry for its high strength properties and easiness of processing. For its reliability continues to be an essential material in aviation and motor-sports, for creating highly reliable lightweight structures (cages, pilot seats, frames, etc.). It is especially required for the highest range in the motor-sports and for professional teams.