Pipe Grade and Steel Grade

The pipe grade for PSL 1 pipe is identical to the steel grade (designated by a steel name) and shall be as given in Table 1. It consists of an alpha or alphanumeric designation that identifies the strength level of the pipe and is linked to the chemical composition of the steel.
NOTE The designations for Grade A and Grade B do not contain any reference to the specified minimum yield strength; however, the numerical portion of other designations correspond with the specified minimum yield strength in SI units or with the upward-rounded specified minimum yield strength, expressed in psi for USC units. The suffix “P” indicates that the steel has a specified phosphorus range.
The pipe grade for PSL 2 pipe shall be as given in Table 1 and consists of an alpha or alphanumeric designation that identifies the strength level of the pipe. The steel name (designating a steel grade), linked to the chemical composition of the steel, additionally includes a suffix that consists of a single letter (R, N, Q or M) that identifies the delivery condition (see Table 3).
NOTE 1 The designation for Grade B does not contain any reference to the specified minimum yield strength; however, the numerical portion of other designations correspond with the specified minimum yield strength in SI units or USC units.
NOTE 2 For sour service, see H.4.1.1.
NOTE 3 For offshore service, see J.4.1.1.
Other steel grade designations (steel numbers) that are used in additional to the steel name in Europe
are given for guidance in Table L.1.