NOTE 1 Experimental and theoretical data relating to manufactured circular hollow sections were not considered when this document was drafted. The application of this document to such structures therefore remains the responsibility of the user.

NOTE 2 The stress design rules of this document can be rather conservative if applied to some geometries and loading conditions for relatively thick-walled shells.

NOTE 3 Thinner shells than r/t = 2 000 can be treated using these provisions but the provisions have not been verified for such thin shells.

NOTE 4 The maximum temperature is restricted so that the influence of creep can be ignored where high temperature creep effects are not covered by the relevant application part.

NOTE 5 Where temperatures outside the above range are involved and the long-term effects of creep are considered negligible, the thermally adjusted properties can be found in EN 1993‑1‑2 or other CEN standards as appropriate. Where no other standard is available, see EN 1993‑1‑2 which, though intended for the design of steel structures against fire, gives general temperature-dependent material properties that can be more widely used (see 5.1(10)).

NOTE 6 Where the effects of creep cannot be ignored, such as where a structure is subject to temperatures above 100 °C for prolonged periods of time, appropriate thermally adjusted properties can be found in other EN standards or established peer-reviewed technical literature.