1045, a medium-carbon steel, has widely recognized equivalents across regions:
ASTM (U.S.): A29 1045, with 0.43–0.50% carbon, 0.60–0.90% manganese, and ≤0.04% phosphorus/sulfur.
EN (Europe): 1.0503 (C45E), featuring 0.42–0.50% carbon and stricter sulfur limits (<0.035%) for better weldability.
JIS (Japan): S45C, with 0.42–0.48% carbon and 0.60–0.90% manganese, commonly used in automotive shafts.
GB (China): 45# steel, matching 1045's chemistry but with slightly higher silicon (0.17–0.37%).
These grades share core properties (tensile strength 570–700 MPa, yield strength 330–350 MPa) and are interchangeable in general engineering, though EN 1.0503 requires additional impact testing for structural use.