Alloy 20 Plates Manufacturer and Supplier

Alloy 20 plates are nickel-iron-chromium austenitic alloy plates specified to ASTM B463 / ASME SB-463 under the UNS designation N08020. The alloy contains 32–38% nickel, 19–21% chromium, 2–3% molybdenum, and 3–4% copper, a composition purpose-built for sulphuric acid service. Niobium stabilisation (8xC min, 1.00 max) prevents sensitisation and intergranular corrosion in welded fabrications.

Minimum tensile strength is 80 ksi (551 MPa), yield strength is 35 ksi (241 MPa), and elongation is 30%. Alloy 20 plates also go by the designations Carpenter 20, 20Cb-3, and W.Nr. 2.4660.

Sachiya Steel International is a reliable manufacturer, supplier, stockist, and exporter of Alloy 20 plates based in Mumbai, India. We’ve maintained over 20 years of experience supplying nickel alloy plates. Our ready inventory exceeds 1,500 to 2,000 metric tons, and we are ISO 9001, ISO 14001, and ISO 45001 certified. Every shipment includes mill test certificates per EN 10204 3.1/3.2, along with seaworthy export packaging.

Plates are available in thicknesses from 1.0 mm to 100 mm, widths up to 2,500 mm, and lengths up to 12,000 mm. Custom cut-to-size options are available on request. Alloy 20 plates serve chemical processing, petrochemical, pharmaceutical, and food processing industries where sulphuric acid resistance and chloride stress corrosion cracking immunity are required.

This page covers the following sections:

Specification
Pricing
Chemical Composition
Mechanical Properties
Equivalent Designation
Industrial Applications
Grade Comparison
Shipping & Packaging
Frequently Asked Questions

Alloy 20 Plate Specifications

The table below lists the specifications of Alloy 20 plates, covering applicable standards, sizes, finishes, and delivery conditions.

Property	Details
Standards	ASTM B463 / ASME SB-463, ASTM A240 / ASME SA-240
Thickness	1.0 mm to 100 mm
Width	Up to 2,500 mm
Length	Up to 12,000 mm
Surface Finish	Mill Finish, 2B, #4 Polished
Form	Hot Rolled, Cold Rolled, Coil-Cut
Delivery Condition	Annealed, Solution Treated

Alloy 20 Plate Sizes

Alloy 20 plates are stocked in a range of standard dimensions. Custom cut-to-size plates can be produced to your project drawings.

Standard Plate Dimensions

We stock plates in the following common ranges:

Dimension	Range
Thickness	1.0 mm to 100 mm (3/16“ to 4“)
Width	Up to 2,500 mm
Length	Up to 12,000 mm

Custom Cut-to-Size Options

Alloy 20 plates are available in custom sizes with precise cutting for flexible, accurate use in many industries.

Parameter	Details
Product	Alloy 20 Plates
Custom Sizing	Available as per buyer specification (non-standard widths and lengths)
Width Tolerance	-0 / +0.499 inches
Length Tolerance	-0 / +0.999 inches
Compliance	As per industry standard cutting tolerances
Ordering Note	Contact with the required dimensions for quotation

Alloy 20 Plate Price

Prices are Rs1,800–2,450 per kg in India and $27 to $65 per kg in USD. The final price depends on plate thickness, size, order quantity, surface finish, and current nickel prices. Plates thicker than 50 mm and non-standard widths are priced higher. For the latest quote for your project, please contact our sales team.

Chemical Composition of Alloy 20 Plates

The chemical composition of Alloy 20 (UNS N08020) is listed below. High copper and niobium content separate this alloy from standard austenitic steels.

Nickel Ni

32.0 - 38.0%

Chromium Cr

19.0 - 21.0%

Iron Fe

Balance

Molybdenum Mo

2.0 - 3.0%

Copper Cu

3.0 - 4.0%

Niobium + Tantalum Nb+Ta

8×C min, 1.00% max

Carbon C

0.07% max

Manganese Mn

2.00% max

Silicon Si

1.00% max

Phosphorus P

0.045% max

Sulphur S

0.035% max

Mechanical Properties

The mechanical properties of Alloy 20 plates, including tensile strength, elongation and hardness, are listed below.

80/551

MPa (ksi)

Tensile Strength (min)

35/241

MPa (ksi)

Yield Strength, 0.2% Offset (min)

Elongation (min)

Property	Value
Tensile Strength (min)	80 ksi (551 MPa)
Yield Strength, 0.2% Offset (min)	35 ksi (241 MPa)
Elongation (min)	30%

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Equivalent Grades of Alloy 20 Plate

International designations equivalent to Alloy 20 Plates, including UNS and Werkstoff Nr., are listed below:

Standard	Designation
UNS	N08020
EN	2.4660
Werkstoff Nr.	2.4660
GB	NS142

Alloy 20 Plate Industrial Applications

Alloy 20 plates are used in high-performing industries that require corrosion resistance. The three key industrial sectors are listed below.

Chemical Processing Industry

Alloy 20 plates are used in sulphuric acid piping systems, heat exchangers, and mixing tanks.

Oil & Gas and Petrochemical

Petrochemical plants use Alloy 20 plates in reactor vessels, process piping, and acid storage tanks.

Pharmaceutical and Food Processing

Alloy 20 plates serve pharmaceutical reactor vessels and food processing equipment.

Alloy 20 Plates vs. Alternative Materials

Buyers often compare Alloy 20 plates with 316L stainless steel, SS 904L, and nickel-based alloys. The comparisons below address the most common selection questions.

Alloy 20 Plates vs. 316L Stainless Steel Plates

Differences in nickel content, corrosion resistance, and cost between Alloy 20 and 316L plates help decide which material is more suitable.

Property / Aspect	Alloy 20 Plates	Stainless Steel 316L Plates
Nickel Content	32–38%	10–14%
Resistance to Chloride SCC	Excellent (practically immune)	Moderate (susceptible under conditions)
Performance in Sulphuric Acid	Superior (low corrosion rates)	Limited resistance
General Corrosion Resistance	High in aggressive chemical environments	Good in mild environments
Suitability – Chemical Processing	Highly suitable	Conditionally suitable
Suitability – Atmospheric Service	Suitable but over-specified	Highly suitable
Cost	Higher	Lower
Typical Applications	Acid handling, chemical, pharma	Marine, food, structural, and general use
Material Selection Recommendation	Use in highly corrosive environments	Use in general or mild service

Alloy 20 Plates vs. SS 904L Plates

Alloy 20 and 904L plates differ in stabilisation, molybdenum content, and corrosion resistance, which affects how they perform in welded, acidic, and chloride environments.

Property / Aspect	Alloy 20 Plates	Stainless Steel 904L Plates
Sulphuric Acid Resistance	Excellent	Excellent
Stabilisation	Niobium stabilised	Not niobium stabilised
Intergranular Corrosion (Welded)	Resistant without PWHT	May require control/treatment
Post-Weld Heat Treatment (PWHT)	Not required in most cases	May be required depending on the service
Molybdenum Content	2–3%	4–5%
Pitting Resistance (Chlorides)	Good	Superior
Weldability	Excellent	Very good
Suitability – Acidic Environments	Highly suitable	Highly suitable
Suitability – Chloride Environments	Moderate	Excellent
Typical Applications	Sulphuric acid service, chemical processing	Marine, offshore, high chloride environments
Material Selection Recommendation	Best for sulphuric acid with welding requirements	Best for high chloride and pitting conditions

Alloy 20 Plates vs. Hastelloy C276 Plates

Alloy 20 and Hastelloy C-276 differ in chemical resistance range and cost, guiding selection for sulphuric acid or aggressive mixed environments.

Property / Aspect	Alloy 20 Plates	Hastelloy C-276 (Ni-Cr-Mo Alloy)
Chemical Resistance Range	Good (focused on sulphuric acid environments)	Excellent (broad spectrum, incl. HCl & oxidising media)
Hydrochloric Acid Resistance	Limited	Excellent
Oxidising Media Resistance	Moderate	Excellent
Sulphuric Acid Performance	Excellent	Excellent
Cost (Relative)	Lower (approx. half the cost)	High
Cost-Effectiveness	High for sulphuric acid-dominant service	Lower unless broad resistance is required
Alloy Composition Type	Ni-Fe-Cr with Cu & Nb stabilisation	Ni-Cr-Mo high-performance alloy
Typical Applications	Chemical processing, sulphuric acid handling	Severe chemical, petrochemical, and pollution control
Material Selection Recommendation	Best for cost-sensitive sulphuric acid use	Best for highly aggressive mixed chemical environments

Shipping & Packaging

Heavy-duty wooden boxes Packing

Export Packaging Standard

We strictly follow seaworthy export handling standards to protect Alloy 20 Plate 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 pipes
Silica gel desiccants to minimize moisture exposure
ISPM-15 fumigated wooden packaging for export

plate Bundle Yard Staging

Container End-Cap Protection

Wrapped Export-Ready Bundles

We Export Worldwide

Sachiya Steel International supplies Alloy steel products to major industrial markets across North America, Europe, the Middle East, Asia and Africa with export-ready documentation and logistics support.

USA
Canada

Frequently Asked Questions

What is the specification for Alloy 20 Plates? +

ASTM B463 / ASME SB-463 is the primary specification for Alloy 20 plates, sheets, and strips in UNS N08020. ASTM A240 / ASME SA-240 also applies.

What sizes are Alloy 20 Plates available in? +

Thicknesses range from 1.0 mm to 100 mm, widths up to 2,500 mm, and lengths up to 12,000 mm. We keep standard sizes in stock and can also supply custom cut-to-size plates on request.

Is Alloy 20 Plate better than 316L Stainless Steel Plate? +

Yes, in sulphuric acid conditions, Alloy 20 plates deliver much better resistance to sulphuric and phosphoric acids, as well as to chloride stress corrosion cracking. With 32–38% nickel, Alloy 20 offers practical immunity to chloride SCC that 316L can’t match.

What is the difference between SS 904L Plates and Alloy 20 Plates? +

Alloy 20 is stabilised with niobium, preventing intergranular corrosion in welded fabrications without post-weld heat treatment. SS 904L has higher molybdenum content (4–5%) for better pitting resistance but lacks niobium stabilisation.

Can Alloy 20 Plates be welded? +

Yes. TIG, MIG, and submerged arc welding can all use ER320LR filler metal. Because it contains niobium, the welds resist corrosion and do not need heat treatment after welding.

What is the price of Alloy 20 Plates per kg? +

Prices are Rs 1,800–2,450 per kg in India and $22–30 USD. The final price depends on thickness, size, quantity, surface finish, and current nickel prices.

What are Alloy 20 Plates used for? +

Sulphuric acid processing equipment, heat exchangers, mixing tanks, pharmaceutical vessels, and food processing applications are the primary uses. The alloy’s combination of acid resistance and weldability drives its selection.

Where can I buy Alloy 20 Plates? +

Sachiya Steel International manufactures standard-size Alloy 20 plates and supplies EN 10204 3.1/3.2 test certificates. We supply custom-cut-to-size plates and export worldwide with seaworthy packaging.