SA240 304H Stainless Steel Plate | High-Temperature 304H

ASTM A240 / ASME SA240 Type 304H (UNS S30409) is a high-carbon austenitic stainless steel plate/sheet grade under ASTM A240/A240M; ASME SA240. This specification page covers grade identity, chemistry, mechanical requirements, related grades, and RFQ practice. Accept material against the ordered edition and the mill test certificate.

Grade Identity and Delivery Condition

ASTM A240 / ASME SA240 Type 304H is supplied for projects that name this designation on the purchase order or calculation sheet. Standard delivery condition is Solution annealed; ASTM grain size No. 7 or coarser for H grades. Gangsteel supplies export plate and related products with EN 10204 documentation. Do not accept an alternate heat-treatment route unless a written concession changes the specification requirement.

Chemical Composition - Heat Analysis (ASTM A240 / ASME SA240 Type 304H)

H-grade carbon floor supports elevated-temperature strength. Grain size No. 7 or coarser required for austenitic H grades.

Element	Min %	Max % / requirement
C	0.04	0.10
Mn	-	<=2.00
Si	-	<=0.75
P	-	<=0.045
S	-	<=0.030
Cr	18.0	20.0
Ni	8.0	10.5

Mechanical Properties (ASTM A240 / ASME SA240 Type 304H)

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

Property	Requirement
Tensile strength, min	515 MPa (75 ksi)
Yield strength (0.2% offset), min	205 MPa (30 ksi)
Elongation in 50 mm, min	40%
Hardness, max	201 HBW / 92 HRB
Delivery condition	Solution annealed; H-grade grain size rules

Related / Near-Equivalent Grades

Near-equivalents are for cross-reference only. They are not automatic code substitutes. Substitution requires engineer approval and matching certificate scope.

System	Grade	Note
ASME	SA240 Type 304H	ASME twin
ASTM	Type 304 / 321H / 347H	Different C/stabilizer strategies
UNS	S30409	304H designation

Frequently Asked Questions

What is ASTM A240 / ASME SA240 Type 304H?

ASTM A240 / ASME SA240 Type 304H (UNS S30409) is a high-carbon austenitic stainless steel plate/sheet under ASTM A240/A240M; ASME SA240. It is ordered when drawings or the calculation sheet name this designation specifically.

What chemical composition applies to ASTM A240 / ASME SA240 Type 304H?

Controlled elements and limits are tabulated above from the governing standard. Always verify the heat analysis on the MTC against the ordered edition.

What mechanical properties should buyers expect for ASTM A240 / ASME SA240 Type 304H?

Tensile, yield, elongation, and related limits are tabulated above. Design allowables must come from the applicable pressure-vessel or structural code, not from a web summary.

What delivery condition is required for ASTM A240 / ASME SA240 Type 304H?

Standard delivery is Solution annealed; ASTM grain size No. 7 or coarser for H grades. State it explicitly on the PO. Do not accept an alternate route without a written concession.

How does ASTM A240 / ASME SA240 Type 304H differ from near-equivalent grades?

Near-equivalents may differ in carbon or alloy bands, tensile class, impact temperature, or heat treatment. Substitution needs engineering approval and matching certificate scope.

How do I RFQ ASTM A240 / ASME SA240 Type 304H from Gangsteel?

Send ASTM A240 / ASME SA240 Type 304H (UNS S30409), thickness x width x length, quantity or tonnage, delivery condition, optional impact/UT/Z tests, EN 10204 3.1 or 3.2, destination, and any dual-mark needs. Gangsteel replies with mill options, lead time, and packing notes.

Ordering and Mill Certificates

State grade ASTM A240 / ASME SA240 Type 304H (UNS S30409), 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.