*The minimum temperature shown is that design minimum temperature for which the material is normally suitable without impact testing other than that required by the material specification. However, the use of a material at a design minimum temperature below −29°C (−20°F) is established by rules elsewhere in this Code, including para. 323.2.2(a) and other impact test requirements. For carbon steels with a letter designation in the Min. Temp. column, see para. 323.2.2(b) and the applicable curve and Notes in Fig. 323.2.2A.