A302 Grade C Equivalents & Cross-Reference

ASTM A302 / A302M Grade C (ASME SA302 Grade C) is frequently cross-referenced to related ASTM/ASME, EN, and other designations. This equivalents page leads with that cross-reference map, then summarizes chemistry and mechanical limits used to judge dual marking. Near-equivalents are not automatic code substitutes.

This page is a standalone technical article. For the primary overview on the original URL, see ASTM A302 / A302M Grade C (ASME SA302 Grade C) primary specification page.

Equivalents and Cross-Reference Map

Use the table for RFQ orientation and dual-cert discussions. True dual certification exists only when one heat meets every chemical and mechanical limit of each named specification on the same MTC. Class society, PED, or ASME dossier wording still controls acceptance.

System	Grade	Note
ASME	SA302 Grade C	ASME twin
ASTM	A302 Grade B	Same tensile class without Ni
ASTM	A302 Grade D	Higher Ni band

Substitution caveat: Do not swap grades based on marketing strength bands alone. Chemistry, heat treatment, impact temperature, and product form must be reviewed by the responsible engineer before any concession.

Chemical Composition - Base Grade (ASTM A302 / A302M Grade C (ASME SA302 Grade C))

Heat and product analyses per A302/A302M. Grade C adds nickel to the Mn-Mo base.

Element / rule	Requirement
C, max (t<=25 mm)	0.20
C, max (25 < t <= 50 mm)	0.23
C, max (t>50 mm)	0.25
Mn	1.07-1.62
P, max	0.025
S, max	0.025
Si	0.13-0.45
Mo	0.41-0.64
Ni	0.37-0.73

Mechanical Properties (ASTM A302 / A302M Grade C (ASME SA302 Grade C))

Confirm thickness, specimen orientation, and any supplementary impact, UT, or hardness requirements on the PO.

Property	Requirement
Tensile strength	80-100 ksi [550-690 MPa]
Yield strength, min	50 ksi [345 MPa]
Elongation in 200 mm, min	17%
Elongation in 50 mm, min	20%
Min thickness	0.25 in [6.5 mm]

Frequently Asked Questions

What are the common equivalents for ASTM A302 / A302M Grade C (ASME SA302 Grade C)?

Buyers typically cross-reference ASTM A302 / A302M Grade C (ASME SA302 Grade C) with the related designations listed in the map above. Related grades in the same family are not automatic substitutes. Primary overview: ASTM A302 / A302M Grade C (ASME SA302 Grade C).

Is a near-equivalent always acceptable on an ASME or PED dossier?

No. The material specification listed on the calculation sheet, PED appraisal, or purchaser material list controls acceptance. Certificate marks must match unless a formal concession is approved.

How should dual marking be requested for ASTM A302 / A302M Grade C (ASME SA302 Grade C)?

List every required standard on the purchase order and ask the mill to print all approved designations on one MTC only when the heat qualifies against each. Gangsteel confirms which heats can honestly carry those marks before allocation.

What is a safe way to compare ASTM A302 / A302M Grade C (ASME SA302 Grade C) with near-equivalents?

Compare chemistry ranges, tensile/yield windows, impact temperature if specified, delivery/heat-treatment practice, and product form side by side. Name-alike grades can still fail dossier acceptance.

Does a sibling class or grade count as an equivalent?

Sibling classes (for example Class 1 vs Class 2, or Grade A vs B) share a family but intentionally different strength or toughness tiers. Ordering the wrong tier undercuts the design assumption.

How do I RFQ ASTM A302 / A302M Grade C (ASME SA302 Grade C) when equivalents are also named?

State ASTM A302 / A302M Grade C (ASME SA302 Grade C) as the governing grade, then list any dual marks required. Include dimensions, quantity, delivery condition, optional tests, certificate type, destination, and which mark governs acceptance.

Ordering and Mill Certificates

State grade ASTM A302 / A302M Grade C (ASME SA302 Grade C), dimensions, quantity, delivery condition, optional NDT/PMI, and certificate (EN 10204 3.1 standard; 3.2 when third-party inspection is ordered). Gangsteel supplies export plate and related products with mill test certificates. Contact Gangsteel for stock and mill production RFQs.