2. Description of standard construction elements

2.1 Tubes

Some manufacturers drill or trepan solid bars to obtain tubes with specific characteristics and dimensions. Although high-powered trepanning machines have been developed in recent years, this practice seems to be declining. However, as the tube trade offers a very limited choice in terms of quality, especially on the French market, this process is still used by those who make use of special steels and heat treatments.

Drilled and hot-forged seamless tubes are commonplace. In the past,...