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
Show All TypesIdentical 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 30 Gray Cast IronGray Cast Iron | Commonly Compared | ASTM A536 Grade 65-45-12 Ductile Cast IronConfidence: HIGH | Fundamental cast iron selection comparison: Class 30 Gray Iron provides 3x higher vibration damping, superior thermal conductivity (48 vs 35 W/(m·K)), and lower casting cost, but 65-45-12 Ductile Iron provides true tensile ductility (12% elongation), specified yield strength (310 MPa), and high impact shock resistance. | |
| ASTM A48 Class 30 Gray Cast IronGray Cast Iron | Commonly Compared | SAE 1018 Carbon SteelConfidence: HIGH | Class 30 Gray Iron offers net-shape casting capability, superior vibration damping, higher compressive strength (~750 vs ~400 MPa), and better machinability for heavy machine bases, whereas SAE 1018 steel provides high tensile elongation (~25%), yield strength, and structural weldability. | |
| EN-GJL-200 Gray Cast IronGray Cast Iron | Commonly Compared | EN-GJL-250 Gray Cast IronConfidence: HIGH | EN-GJL-200 is more easily cast in thin complex walls without chilling, but EN-GJL-250 provides higher tensile and compressive strength for machine tools. |