ASTM A387 Gr.5 Plate Specifications

The table below outlines ASTM A387 Gr.5 plate key supply and specification parameters.

Parameter Details
Standard ASTM A387 / ASME SA-387
Class Class 1, Class 2
Thickness Range 6 mm to 300 mm
Width Range 3000 mm
Length Range 12000 mm
Delivery Condition Normalised, Normalised & Tempered, Quenched & Tempered
Surface Finish Hot Rolled, Sandblasted, Mill Finish

Available Sizes of ASTM A387 Gr.5 Plates

ASTM A387 Grade 5 alloy steel plates are stocked in standard mill sizes and can be supplied cut-to-size for specific project requirements. The following ranges are typically available.

Dimension Range
Thickness 6 mm to 150 mm (1/4" to 6")
Width Up to 3000 mm (up to 120")
Length Up to 12000 mm (up to 480")
Custom sizes Cut-to-size available on request

ASTM A387 Gr.5 Plate Price

ASTM A387 Grade 5 usually costs between ₹100 and ₹150 per kg in India, with lower prices available for large bulk orders. In international markets, prices are generally between USD $1.20 and $2.50 per kg, depending on the plate thickness, class, and country of origin. Class 2 plates are costlier than Class 1 plates because they require additional heat treatment. The final price is also affected by the mill where the plate is produced, the size of the order, the heat treatment condition, and the testing requirements.

ASTM A387 Gr.5 Plate Chemical Composition

The table below lists the full chemical composition of A387 Grade 5 plates as specified by the standard.

The high chromium range separates Grade 5 from lower-chromium A387 grades. It forms a stable oxide layer that resists sulfidation and high-temperature oxidation in refinery and petrochemical service.

Carbon C
0.15% max
Manganese Mn
0.30 - 0.60%
Phosphorus P
0.035% max
Sulfur S
0.035% max
Silicon Si
0.50% max
Chromium Cr
4.00 - 6.00%
Molybdenum Mo
0.45 - 0.65%

ASTM A387 Gr.5 Plate Mechanical Properties

ASTM A387 Grade 5 plates come in two classes. Class 1 has lower strength for moderate use, while Class 2 has higher strength for tougher conditions. Both have the same chemistry; only the heat treatment and resulting strength differ.

70-95 / 485-655
ksi / MPa
Tensile Strength (Class 2)
45 / 310
ksi / MPa
Yield Strength, 0.2% Offset (Class 2, min)
18
%
Elongation in 50 mm (min)

Class 1 Mechanical Properties

Class 1 properties work well for pressure vessel parts that need lower hardness and easier machining. The values below show the minimum levels required by ASTM A387.

Property Value
Tensile Strength 415 to 585 MPa (60 to 85 ksi)
Yield Strength (0.2% offset) 205 MPa min (30 ksi)
Elongation in 200 mm 22% min
Elongation in 50 mm 18% min

Class 2 Mechanical Properties

Class 2 plates are specified for higher-pressure or more demanding designs. They require more controlled normalising and tempering to achieve the elevated strength values.

Property Value
Tensile Strength 485 to 655 MPa (70 to 95 ksi)
Yield Strength (0.2% offset) 310 MPa min (45 ksi)
Elongation in 50 mm 18% min
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ASTM A387 Gr.5 Plate Equivalent Designations

Buyers procuring UNS K41545 across different national standards can cross-reference using the table below.

Standard / System Designation
UNS (USA) K41545
EN / DIN (Europe) X12CrMo5
Werkstoff Nr. 1.7362
JIS (Japan) G4109 SCMV 5

ASTM A387 Gr.5 Plate Applications

ASTM A387 Grade 5 plates are used in equipment that must safely hold pressure at high temperatures. Their 5Cr-0.5Mo alloy gives them strong resistance to hydrogen damage and sulfur attack, so they perform well in hot and corrosive conditions.

Petroleum Refining & Petrochemical Industry

A387 Grade 5 plates are used in catalytic cracking units, hydroprocessing reactors and desulfurisation vessels. The 5% chromium content resists sulfur compound attack at temperatures where lower-chromium grades would corrode rapidly.

Power Generation

Cr-Mo plates in this grade serve as components in high-temperature boiler drums, heat recovery steam generators (HRSGs), and superheater headers. The alloy maintains its creep strength through prolonged thermal cycling.

Chemical Processing

Chemical reactor vessels handling hydrogen-rich streams at elevated temperatures rely on 5Cr-0.5Mo plates. They resist hydrogen attack, where carbon steel and low-chromium alloys become susceptible to decarburisation.

ASTM A387 Gr.5 vs. Other A387 Grades

The comparison below covers the three grades most commonly evaluated alongside ASTM A387 Gr.5: Grade 11, Grade 22 and Grade 9. Grade 5 (5Cr-0.5Mo) sits in the middle of the A387 chromium-molybdenum family. Grade selection depends on operating temperature, corrosion environment and hydrogen partial pressure.

ASTM A387 Gr.5 vs. Gr.11 (1.25Cr-0.5Mo)

ASTM A387 Grade 5 and ASTM A387 Grade 11 plates mainly differ in chromium content, which affects the temperature ranges they can handle and their resistance to sulfidation.

Property ASTM A387 Gr.5 ASTM A387 Gr.11
Chromium Content 4.00 – 6.00% 1.25%
Molybdenum Content 0.45 – 0.65% 0.45 – 0.65%
Temperature Resistance Above 450°C Up to 400°C
Sulfidation Resistance High (preferred for high-temp service) Moderate
Typical Application Refinery hydroprocessing equipment Moderate sulfur, lower temp service
Cost Higher (premium alloy) More economical
Preferred Service High-temp, high-sulfur environments Services below 400°C (750°F)

ASTM A387 Gr.5 vs. Gr.22 (2.25Cr-1Mo)

ASTM A387 Grade 22 plates and A387 Grade 5 have very different chromium levels. This affects how well they resist oxidation, how easy they are to fabricate, the temperatures they can handle in service, and their overall cost.

Property ASTM A387 Gr.5 ASTM A387 Gr.22
Chromium Content 4.00 – 6.00% 2.25%
Molybdenum Content 0.45 – 0.65% 1.00%
Sulfidation Resistance Higher (due to more chromium) Moderate
Creep Rupture Properties Moderate Slightly better (higher molybdenum)
Primary Strength Corrosion & oxidation resistance High-temperature creep strength
Typical Application Refinery & petrochemical equipment Power generation pressure vessels
Usage Less common than Gr.22 One of the most widely used Cr-Mo grades
Best Chosen When Corrosion resistance is a priority High-temperature strength is a priority

ASTM A387 Gr.5 vs. Gr.9 (9Cr-1Mo)

ASTM A387 Grade 5 and ASTM A387 Grade 9 plates vary significantly in chromium content, influencing their oxidation resistance, fabricability, service temperature range and overall cost.

Property ASTM A387 Gr.5 ASTM A387 Gr.9
Chromium Content 4.00 – 6.00% 9.00%
Molybdenum Content 0.45 – 0.65% 0.90 – 1.10%
Oxidation Resistance Good Superior
Sulfidation Resistance Good Higher (due to more chromium)
Typical Service Temperature 450°C to 550°C Above 550°C (1020°F)
Fabricability Easier to fabricate More challenging
Cost Lower Higher
Best Chosen When Balanced performance & cost needed Maximum oxidation & sulfidation resistance required

Shipping & Packaging

Main export packaging setup Heavy-duty wooden boxes Packing
Export Packaging Standard

We strictly follow seaworthy export handling standards to protect ASTM A387 Gr.5 Plates from transit damage, moisture ingress, and surface contamination during long-distance dispatch.

  • Heavy-duty wooden boxes with moisture barrier lining
  • HDPE stretch film wrapping on all bundles
  • Plastic end caps on threaded and plain-end plate
  • Silica gel desiccants to minimize moisture exposure
  • ISPM-15 fumigated wooden packaging for export
shipping preparation Plate Bundle Yard Staging
Shipping packaging Container End-Cap Protection
Shipping stock Wrapped Export-Ready Bundles

We Export Worldwide

Sachiya Steel International supplies ASTM A387 Gr.5 Plates to major industrial markets across North America, Europe, the Middle East, Asia and Africa with export-ready documentation and logistics support.

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Frequently Asked Questions: ASTM A387 Gr.5 Plates

What is the difference between ASTM A387 Gr.5 class 1 and class 2 plates?+
Class 2 plates have higher minimum tensile and yield strength than Class 1. Class 1 requires 415 to 585 MPa (60 to 85 ksi) tensile strength and 205 MPa (30 ksi) yield strength. Class 2 requires 485 to 655 MPa (70 to 95 ksi) tensile and 310 MPa (45 ksi) yield. The chemical composition is identical; only the heat treatment and resulting mechanical properties differ.
What sizes are ASTM A387 Gr.5 Plates available in?+
A387 Grade 5 plates are available in thicknesses from 6 mm to 150 mm (1/4" to 6"), widths up to 3000 mm (120"), and lengths up to 12000 mm (480"). Cut-to-size plates are available on request for non-standard dimensions.
What is the maximum service temperature for ASTM A387 Gr.5 Plates?+
ASTM A387 Gr.5 plates can operate at temperatures up to 593°C (1100°F) in oxidising and sulfidising environments. The 5Cr-0.5Mo composition provides stable mechanical properties and corrosion resistance within this range.
Do ASTM A387 Gr.5 Plates require post-weld heat treatment (PWHT)?+
Yes. Post-weld heat treatment (PWHT) is mandated for ASME code fabrication involving 5Cr-0.5Mo material. For A387 Grade 5, the standard PWHT temperature range is 720°C to 750°C (1325°F to 1380°F), and the duration of the hold is contingent upon the plate's thickness. This process is essential for mitigating residual stress and reinstating toughness within the heat-affected zone.
What is the ASME equivalent of ASTM A387 Grade 5?+
The ASME equivalent of ASTM A387 Grade 5 is ASME SA-387 Grade 5. ASME adopts ASTM A387 with the SA- prefix for use in ASME Boiler and Pressure Vessel Code construction.
Can ASTM A387 Gr.5 Plates be used in hydrogen service?+
A387 Grade 5 plates are suitable for hydrogen service within the limits defined by Nelson curves. The 5% chromium content raises the hydrogen attack threshold compared to carbon steel and lower-chromium Cr-Mo grades.
What mill certifications are supplied with ASTM A387 Gr.5 Plates?+
Every plate ships with a mill test certificate (MTC/MTR) per EN 10204. The certificate includes chemical analysis, mechanical test results (tensile, yield, elongation), heat number traceability, and plate dimensions.
How does ASTM A387 Gr.5 compare to Gr.11 for refinery service?+
Grade 5 contains 4.00 to 6.00% chromium versus Gr.11's 1.00 to 1.50%. This higher chromium level gives Gr.5 superior sulfidation resistance and a higher hydrogen attack threshold. For refinery service above 450°C (840°F) with significant sulfur or hydrogen exposure, Grade 5 is the stronger choice.

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