EN 2137:2017

Overview

EN 2137:2017 (published as SIST EN 2137:2018) is a CEN/AeroSpace standard that specifies requirements for Steel FE-PL75 in bar form for aerospace applications. It covers low-alloy, high-strength bars with an overall tensile strength range of 1 100 MPa to 1 250 MPa and nominal bar diameters De ≤ 100 mm. The standard gives chemical composition limits, production and heat-treatment methods, delivery conditions and test/inspection references used by manufacturers, purchasers and regulators in the aerospace supply chain.

Key topics and requirements

• Material designation: Steel FE-PL75 (low-alloy general purpose steel for aerospace).
• Tensile strength: Primary range 1 100–1 250 MPa (reference values and test conditions are included in the standard).
• Chemical composition (typical limits given):
  • Carbon (C) 0.26–0.33%, Silicon (Si) 0.10–0.40%, Manganese (Mn) 0.20–0.60%
  • Phosphorus (P) ≤ 0.025%, Sulfur (S) ≤ 0.020%
  • Chromium (Cr) 1.20–1.50%, Molybdenum (Mo) 0.30–0.60%, Nickel (Ni) 3.30–4.30%
• Production: Bars produced from air-melted metal; applicable forms include drawn, ground or rolled bars with De ≤ 100 mm.
• Heat treatment and delivery conditions: Annealed and hardened & tempered conditions are specified; reference heat treatment example is hardening ~850 °C (±10 °C) followed by tempering ~585 °C (±5 °C) - consult the standard for exact cycles and acceptance criteria.
• Mechanical and hardness requirements: Strength, proof stress and hardness values are specified according to test pieces and delivery conditions; mechanical testing and dimensional inspections are required as per the tables.
• Inspection and qualification: Marking, dimensional inspection and a purchaser–manufacturer qualification programme are referenced.

Applications and users

• Practical uses: selection and procurement of high-strength aerospace bars where high tensile performance and controlled chemistry are required (e.g., structural components, machined parts and other mechanical elements in aerospace systems).
• Who uses this standard:
  • Aerospace OEMs and tier suppliers specifying raw material requirements
  • Steel bar manufacturers and heat-treatment shops producing FE-PL75 bars
  • Procurement, quality and inspection personnel verifying compliance
  • Design and materials engineers selecting alloys for high-strength applications

Related standards

• EN 2034 to EN 2042 series - dimensions and tolerances for round, hexagonal, rectangular and square aerospace bars
• EN 4258 - organization of aerospace metallic material standards
• EN 4500-005 - rules for drafting and presentation of steel material standards
• EN 4700-002 - technical specification for wrought steel bars and sections

EN 2137:2017 is maintained under ASD-STAN and adopted by CEN members; consult the full standard for definitive test methods, tables and contractual requirements when specifying Steel FE-PL75 for aerospace use.