Equivalent Grades & Cross-Reference
Cross-reference designations across UNS, EN/DIN, ISO, SAE, and JIS standards. Comparable does not mean directly interchangeable. Always verify composition tolerance limits and mechanical requirements.
International standard designations are established by distinct standards bodies with differing testing standards (e.g. ASTM E8 vs ISO 6892-1). Even when chemical compositions overlap, allowable trace impurities (such as phosphorus, sulfur, or iron), grain size requirements, temper nomenclature, and minimum elongation criteria can differ.
Never authorize a structural alloy substitution without verifying the governing procurement specification, temper, ruling section size, and environmental compatibility.
Relationship Classification Governance
Identical chemical composition and mechanical requirements across different naming authorities.
Rule: Direct 1:1 dual specification permissible subject to certified mill test reports (MTR).Officially recognized counterpart in another national or international engineering standard (e.g. ASTM to EN).
Rule: Chemical limits or testing protocols may have subtle differences (e.g. tighter P/S ceilings or impact requirements). Engineering review required before substitution.Substantially identical chemistry and overlapping mechanical envelope, but slight variations in allowable trace elements or testing protocols exist across governing standards.
Rule: Direct commercial substitution is generally permissible subject to certified Mill Test Report (MTR) confirmation for critical applications.Similar base alloy chemistry and general functional properties, but noticeable divergence in allowable impurity ceilings, cold-work response, or minimum yield requirements.
Rule: Engineering substitution review required. Design calculations must verify temper, formability, and corrosion limits before specifying as a direct replacement.Similar base chemistry and functional performance envelope, but not officially harmonized by standards organizations.
Rule: Comparable does not mean equivalent. Heat treatment response and dimensional tolerances may diverge.Close metallurgical alternative when the primary grade is unavailable or obsolete.
Rule: Design parameters (weldability, hardenability, fatigue limit) must be re-evaluated for the specific application.Frequently evaluated side-by-side during trade-off studies or alloy selection.
Rule: Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).Materials superficially mistaken for equivalents that exhibit critical metallurgical incompatibilities.
Rule: DO NOT SUBSTITUTE without full engineering re-qualification.| Source Alloy (UNS) | Relationship Type | Target Grade / Standard | Engineering Scope & Nuance | Actions |
|---|---|---|---|---|
| ASTM A48 Class 50 Gray Cast IronGray Cast Iron | Commonly Compared | ASTM A536 Grade 80-55-06 Ductile Cast IronConfidence: HIGH | High-strength selection: Class 50 Gray Iron delivers maximum damping and compressive rigidity without magnesium nodulizing treatments, whereas 80-55-06 Ductile Iron offers 60% higher tensile strength (552 vs 345 MPa) and 6% elongation. | |
| ASTM A536 Grade 65-45-12 Ductile Cast IronDuctile (Nodular) Iron | Commonly Compared | ASTM A536 Grade 80-55-06 Ductile Cast IronConfidence: HIGH | Tradeoff between ductility and strength: 65-45-12 provides double the elongation (12% vs 6%) and superior impact resistance, while 80-55-06 offers 23% higher yield strength (379 vs 310 MPa) and increased wear resistance due to higher pearlite fraction. | |
| ASTM A536 Grade 65-45-12 Ductile Cast IronDuctile (Nodular) Iron | Approximate Equivalent | EN-GJS-400-15 Ductile Cast IronConfidence: HIGH | EN-GJS-400-15 (min 400 MPa UTS, 250 MPa YS, 15% elongation) is the nearest European counterpart to ASTM A536 65-45-12 (min 448 MPa UTS, 310 MPa YS, 12% elongation). Both serve general mechanical engineering and pressure vessel roles. | |
| ASTM A536 Grade 80-55-06 Ductile Cast IronDuctile (Nodular) Iron | Commonly Compared | ASTM A536 Grade 100-70-03 Ductile Cast IronConfidence: HIGH | 80-55-06 provides higher elongation (6% vs 3%) in the as-cast state without thermal normalizing, while 100-70-03 achieves 25% higher tensile strength (689 vs 552 MPa) through full pearlite normalization. | |
| ASTM A536 Grade 80-55-06 Ductile Cast IronDuctile (Nodular) Iron | Approximate Equivalent | EN-GJS-600-3 Ductile Cast IronConfidence: MEDIUM | EN-GJS-600-3 (min 600 MPa UTS, 370 MPa YS, 3% elongation) and ASTM A536 80-55-06 (min 552 MPa UTS, 379 MPa YS, 6% elongation) address similar high-strength drivetrain components. | |
| EN-GJS-500-7 Ductile Cast IronDuctile (Nodular) Iron | Approximate Equivalent | ASTM A536 Grade 80-55-06 Ductile Cast IronConfidence: HIGH | EN-GJS-500-7 (min 500 MPa UTS, 320 MPa YS, 7% elongation) and ASTM A536 80-55-06 (min 552 MPa UTS, 379 MPa YS, 6% elongation) occupy comparable medium-strength engineering positions with mixed ferritic-pearlitic matrices. | |
| EN-GJS-500-7 Ductile Cast IronDuctile (Nodular) Iron | Commonly Compared | EN-GJS-600-3 Ductile Cast IronConfidence: HIGH | EN-GJS-500-7 provides higher impact elongation (7% vs 3%), whereas EN-GJS-600-3 provides higher proof stress (370 vs 320 MPa) and better abrasive wear endurance. |