API 5L standard material grade: PSL-1, PSL-2.
API Spec 5L pipeline pipe application: used for gas, water and oil transportation in oil and gas industry.

API 5L gr B pipeline pipe chemical composition requirements:
API 5L gr B PSL-1: C ≤ 0.28%, Mn ≤ 1.20%, P ≤ 0.030%, S ≤ 0.030%, Nb + V + Ti ≤ 0.15%, Cu ≤ 0.50%, Ni ≤ 0.50%, Cr ≤ 0.50%, Mo ≤ 0.15%.

API 5L gr B PSL-2: L245N / BN steel grade: C ≤ 0.24%, Si ≤ 0.40%, Mn ≤ 1.20%, P ≤ 0.025%, S ≤ 0.015%, Nb + V + Ti ≤ 0.06%, Ti ≤ 0.04%, Cu ≤ 0.50%, Ni ≤ 0.30%, Cr ≤ 0.30%, Mo ≤ 0.15%, B ≤ 0.004%.

L245M / BM grade: C ≤ 0.22%, Si ≤ 0.45%, Mn ≤ 1.20%, P ≤ 0.025%, S ≤ 0.015%, Nb ≤ 0.05%, V ≤ 0.05%, Ti ≤ 0.04%, Cu ≤ 0.50%, Ni ≤ 0.30%, Cr ≤ 0.30%, Mo ≤ 0.15%, B ≤ 0.004%.

API 5L gr B pipeline pipe tensile test requirements:
API 5L gr B PSL-1: yield strength ≥ 245MPa, tensile strength ≥ 425MPa

API 5L gr B PSL-2: yield strength 245MPa - 450MPa, tensile strength: 415MPa - 655MPa, yield strength ratio ≤ 0.93.