SA387Gr11CL2 Equivalents & Cross-Reference

ASME SA387 / ASTM A387 Grade 11 Class 2 (1.25Cr-0.5Mo) pressure-vessel plate is frequently cross-referenced to EN, other ASTM Cr-Mo grades, and Class 1 of the same grade. This equivalents page leads with that cross-reference map, then summarizes the base-grade chemistry and Class 2 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 ASME SA387 / ASTM A387 Grade 11 Class 2 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	Comparable grade	Cross-reference note
ASTM	A387 Grade 11 Class 2	Base ASTM product form
ASME	SA387 Grade 11 Class 2	ASME twin used on Section VIII vessels
ASTM / ASME	A387 / SA387 Grade 11 Class 1	Same chemistry family, lower tensile class
EN 10028-2	13CrMoSi5-5 (approx.)	1.25Cr-Mo-Si European pressure family - confirm edition
ASTM	A387 Grade 12 Class 2	Related Cr-Mo; different Cr/Mo band
ASTM	A387 Grade 22 Class 2	2.25Cr-1Mo family - not interchangeable

Substitution caveat: Do not swap Grade 11 Class 2 for Grade 12/22, or for EN 13CrMo4-5 / 10CrMo9-10, without engineering review of design temperature, PWHT, and toughness. Class 1 vs Class 2 tensile windows are intentional; lifting Class on paper without MTC proof is non-conforming.

Chemical Composition - Heat Analysis (A387 Grade 11)

Heat analysis for Grade 11. Product analysis tolerances apply per A387/SA387. Confirm the ordered edition on the MTC.

Element	Heat analysis %
C	0.05 to 0.17
Mn	0.40 to 0.65
P	<=0.025
S	<=0.025
Si	0.50 to 0.80
Cr	1.00 to 1.50
Mo	0.45 to 0.65

Mechanical Properties - Class 2

Class 2 tensile requirements for Grade 11. State Class 2 explicitly on the PO; Class 1 is a different strength tier.

Requirement	Class 2 (Grade 11)
Tensile strength	75 to 100 ksi [515 to 690 MPa]
Yield strength, min	45 ksi [310 MPa]
Elongation in 50 mm, min	22%
Elongation in 200 mm, min	18%
Delivery / HT	Per A387/SA387; Grade 11 tempering generally >=620 deg C

Frequently Asked Questions

What are the common equivalents for SA387 Grade 11 Class 2?

Buyers typically cross-reference ASTM A387 Gr 11 Cl2 with ASME SA387 Gr 11 Cl2, A387 Gr 11 Cl1 (same chemistry, lower tensile), and EN 10028-2 13CrMoSi5-5 as an approximate European Cr-Mo-Si counterpart. Related ASTM grades 12 and 22 are neighboring Cr-Mo families, not drop-in equals. Primary overview: SA387Gr11CL2.

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. If the dossier says SA387 Grade 11 Class 2, the certificate must carry that mark unless a formal concession is approved.

How should dual marking be requested for SA387Gr11CL2?

List every required standard on the purchase order (for example ASTM A387 + ASME SA240-style dual is wrong family; use A387 + SA387, or A387 + EN grade only when the heat qualifies). Ask the mill to print all approved designations on one MTC. Gangsteel confirms which heats can honestly carry those marks before stock allocation or rolling.

What is a safe way to compare SA387 Gr11 Cl2 with EN 13CrMoSi5-5 or Grade 12?

Compare chemistry ranges (Cr, Mo, Si), Class tensile windows, impact temperature if specified, delivery/PWHT practice, and product form side by side. Grade 12 and Grade 22 change the alloy balance; EN names that look similar may still differ on Si, toughness, and thickness limits.

Does Class 1 count as an equivalent to Class 2?

Class 1 shares Grade 11 chemistry but uses a lower tensile band. It is a related class, not a strength-equivalent substitute for Class 2 designs. Ordering Class 1 against a Class 2 drawing undercuts the design tensile assumption.

How do I RFQ SA387 Grade 11 Class 2 when equivalents are also named?

State ASME SA387 or ASTM A387 Grade 11 Class 2 as the governing grade, then list any dual marks required. Include thickness x width x length, quantity, heat-treatment condition, impact/UT if any, certificate type, and destination. Clarify which mark is governing for acceptance.

Ordering and Mill Certificates

State grade ASME SA387 / ASTM A387 Grade 11 Class 2, 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.