The designation EN 10028:3 P355NL1 shows that this is steel for pressure purposes (P) with minimum yield strength of 355 MPa (355) which is impact tested in the transverse direction at -40 deg C (NL1). EN 10028:3 P355NL2 follows the same pattern but is impact tested at -50 deg C.
P355NH / 1.0565 - SteelNumber - Chemical composition EN 10028-3:2009 Flat products made of steels for pressure purposes. Weldable fine grain steels, normalized:EN 10222-4:1999 Steel forgings for pressure purposes.PN-EN 10216-3 ||Seamless steel tubes for pressure P275NL1, P355NL1, P460NL1, P620QL, P690QL1 For special applications in low temperatures P275NL2, P355NL2, P460NL2, P690QL2. Details:Table 1. Dimensions and tolerances:Details:Table 2:Pipe lengths:Pipes with precise lengths are manufactured with the following tolerance values:- for pipes 0-6m -0/+10% - for pipes 6-12m -0/+15%