What Makes Ganpat Industrial Corporation Your Trusted Alloy Steel Gr 11 Plate Partner?
Since 1997
Nearly three decades supplying chrome-moly and alloy steel plate to Indian fabricators
Manufacturer & Stockist
Forged bars, fasteners and flanges plus stocked pipes, plates and tubes in every grade
ISO 9001:2015
Quality management system independently audited and renewed every year
PED & Petrofac Approved
Cleared for European pressure equipment projects and Petrofac vendor lists
Full Documentation
Heat-wise mill test certificate, PMI report and UT record on every plate
Alloy Steel Gr 11 Plate Functionalities
- 1Material Basis: 1.25Cr-0.5Mo-Si Low Alloy Steel • UNS K11789
- 2Governing Standard: ASTM A387 Gr 11 • ASME SA387 Gr 11 • Class 1 & Class 2
- 3Thickness Range: 5mm To 150mm, Width Up To 3000mm
- 4Weld Number: P-No. 4, Group No. 1 Per ASME Section IX
- 5Equivalents: EN 1.7336 (13CrMoSi5-5) • JIS SCMV3
- 6Forms Supplied: Plate, Sheet, Coil, Shim Sheet, Strip & Chequered Plate
Mumbai works desk • WhatsApp +91 85912 64209 • Same-day thickness-wise quote
Ganpat Industrial Corporation has supplied Indian and export fabricators since 1997. Alloy Steel Gr 11 Plate features 1.25% chromium, 0.5% molybdenum, and 0.5-0.8% silicon. This chemistry holds strength at elevated temperatures and resists oxidation in sour service. We are an established Alloy Steel Gr 11 Plate Supplier in India. We stock ASTM A387 Grade 11 Class 1 and Class 2 plates. Available plate thicknesses range from 5mm to 150mm. Every plate is rolled to ASTM A6 flatness and thickness tolerance. We machine, shear, and test each heat at our Mumbai facility. Every despatch carries an EN 10204 3.1 mill test certificate. A 3.2 third-party witnessed certification is available on request. We regularly supply this grade to Vadodara, Chennai, and Kandla fabricators. We also export to Dubai, Jebel Ali, and Houston.
Mumbai · Chromium-Molybdenum Pressure Vessel Plate Stockist & Exporter
Alloy Steel Gr 11 Plate Built For Welded Boilers And Pressure Vessels At Elevated Temperature
Ganpat Industrial is a driven-pricing Alloy Steel Gr 11 Plate Supplier in India. We stock ASTM A387 Grade 11 Class 1 and Class 2 plate from 5mm to 150mm thickness, hot rolled and heat treated in-house.
- ✓ISO 9001:2015
- ✓ISO 14001:2015
- ✓OHSAS 18001:2007
- ✓PED Certified
- ✓Petrofac Approved
UNS Designation
K11789
P-No. 4, Group No. 1
Nominal Chemistry
1.25Cr-0.5Mo-Si
Chromium 1.00-1.50%, Molybdenum 0.45-0.65%
Governing Standard
ASTM / ASME A387
Class 1 (Annealed / N&T) & Class 2 (N&T)
Thickness Range
5 – 150 mm
Width up to 3000mm, length up to 12000mm
Explore ASTM A387 Grade 11 Sheet Manufacturer in India with MTC EN 10204 3.1/3.2 Certification
Specification Of Alloy Steel Gr 11 Plate
We check every Alloy Steel ASTM A387 GR 11 Plates order against specification sheets.
Material Basis
- 1.25Cr-0.5Mo-Si Low Alloy Steel
- UNS K11789
- Killed Steel, Heat Treated
- Normalised, Annealed Or Q&T
Governing Plate Standards
- ASTM A387 Grade 11
- ASME SA387 Grade 11
- Class 1 & Class 2
- ASME Section II Part D Listed
Plate Size Range
- Thickness 5mm To 150mm
- Width Up To 3000mm
- Length Up To 12000mm
- Shim & Sheet Down To 0.5mm
Product Forms Supplied
- Alloy Steel Gr 11 Hot Rolled Plates
- ASTM A387 Cr-Mo Gr 11 Cold Rolled Sheets
- Gr 11 Alloy Steel Chequered Plates
- ASTM A387 Alloy Steel Gr 11 Coils
Delivery Condition
- Hot Rolled, Killed Steel
- Normalised & Tempered (Class 2)
- Tempering 620°C [1150°F] Min
- Edges Sheared Or Flame Cut
Surface Finish Options
- Cr-Mo Gr 11 #4 Finish Plates
- Chromium Molybdenum Gr 11 2B Finish Plates
- Alloy Steel Gr 11 #8 Mirror Finish Plates
- Natural Hot Rolled & Pickled
Testing Offered
- PMI Spectro Analysis
- Ultrasonic Testing Per ASTM A435
- Hardness & Tensile Test
- Third Party Inspection
Matching Products
- ASME SA387 Alloy Steel Gr 11 Sheets
- Alloy Steel Class 1 Gr 11 Plates
- A387 Grade 22 & Grade 12 Plate
- Gr 11 Forged Rings & Flanges
Packing
- Bundled & Strip Strapped
- Wooden Crates, Fumigated For Export
- Heat Number & Grade Tags
- VCI Wrap For Sea Freight
Types Of Alloy Steel Gr 11 Plates We Supply
A dependable Alloy Steel Gr 11 Plate Manufacturer in India stocks all common forms.
Alloy Steel Gr 11 Hot Rolled Plates
HR
ASTM A387 Cr-Mo Gr 11 Cold Rolled Sheets
CR
ASTM A387 Alloy Steel Gr 11 Coils
Coil
Alloy Steel Gr 11 Shim Sheets
Shim
UNS K11789 Strips
Strip
Cr-Mo Gr 11 #4 Finish Plates
#4 Finish
Chromium Molybdenum Gr 11 2B Finish Plates
2B Finish
Alloy Steel Gr 11 #8 Mirror Finish Plates
#8 Mirror
ASTM A387 Alloy Steel Gr 11 Coils Size Chart
A trusted Alloy Steel Gr 11 Plate Supplier in India maintains a ready stock.
| Product Form | Thickness | Width | Length |
|---|---|---|---|
| Plate, Class 1 / Class 2 | 5mm – 150mm | 1500mm – 3000mm | 6000mm – 12000mm |
| Sheet | 1.6mm – 5mm | 1000mm – 2000mm | 2000mm – 6000mm |
| Shim Sheet | 0.5mm – 3mm | 1000mm – 1250mm | Coil / Cut Length |
| Coil | 1mm – 6mm | 1000mm – 1500mm | Coil Form |
| Strip | 0.5mm – 6mm | Up To 600mm | Coil / Cut Length |
| Chequered Plate | 5mm – 12mm | 1250mm – 2000mm | 2500mm – 6000mm |
Cr-Mo Gr 11 Plate Dimensional Tolerance
Thickness, flatness and squareness are checked to ASTM A6/A6M before dispatch.
Thickness Tolerance
Per ASTM A6 Table
Varies by thickness and width class
Flatness
Std Or Close
Close flatness on request for machining stock
Width & Length
+13mm / -0mm
Typical sheared-edge allowance
Squareness
Per ASTM A6
Checked on every sheared plate
Need Chromium Molybdenum Gr 11 CR Sheets In A Hurry?Mail the thickness list, we quote inside 24 hours, mill-direct on bulk tonnage too.
Buy Cr-Mo Gr 11 Cl1/Cl2 Cold Rolled & Hot Rolled Plates in Hot Rolled Finish for Boiler, Pressure Vessel & Power Plant Applications
SA 387 Gr 11 Class 1 vs Class 2 Plate
An Alloy Steel Gr 11 Plate Supplier in India guarantees full mill test certification.
Class 1 Plate
- Tensile 415 – 585 MPa, yield 240 MPa min
- Usually annealed or N&T condition
- Slightly better ductility for cold forming
- Preferred where lower design stress suffices
Class 2 Plate
- Tensile 485 – 620 MPa, yield 310 MPa min
- Normalised & tempered / quenched & tempered
- Higher allowable design stress at elevated temp
- Preferred for thick-wall, high-pressure vessels
Alloy Steel Gr 11 Hot Rolled Plates Manufacturing & Heat Treatment
From Slab To Certified Plate
How UNS K11789 stock becomes a finished, traceable pressure vessel plate at our works.
Slab Hot Rolling
Cr-Mo slab hot rolled down to ordered thickness
Normalising / Q&T
Heated above critical, air or liquid quenched then tempered
Shearing & Sizing
Edges sheared or flame cut to ordered width and length
Inspection
Chemistry, mechanical tests and UT cleared against MTC
Dispatch
Heat-number tagged and shipped with EN 10204 3.1 certificate
ASTM A387 Grade 11 Plate Chemical Composition
Heat analysis limits for Alloy Steel Gr 11 Sheets under ASTM A387/A387M, identical for Class 1 and Class 2.
IronFe
Balance
ChromiumCr
1.00 – 1.50%
SiliconSi
0.50 – 0.80%
MolybdenumMo
0.45 – 0.65%
ManganeseMn
0.40 – 0.65%
CarbonC
0.05 – 0.17%
PhosphorusP
0.025% max
SulphurS
0.025% max
SA 387 Gr 11 Class 1 Sheets Mechanical Properties
Minimum & Range Values, As Tested Per ASTM A370
Alloy Steel Class 1 Gr 11 Plates and Class 2 plates share one chemistry but two different strength levels.
Class 1 Tensile Strength
415 – 585 MPa
60 – 85 ksi
Class 2 Tensile Strength
485 – 620 MPa
70 – 90 ksi
Class 1 Yield Strength, Min
240 MPa
35 ksi min
Class 2 Yield Strength, Min
310 MPa
45 ksi min
Elongation In 2 In [50mm]
22% Min
Applies to both Class 1 and Class 2
P-Number / Group
P-No. 4 / Gr. 1
Per ASME Section IX QW-422
Heat Treatment
Anneal / N&T / Q&T
Tempered 620°C [1150°F] min
Impact Testing
On Request
Charpy V-notch per purchaser specification
Physical Properties Of Alloy Steel Class 1 Gr 11 Plates
A trusted Cr-Mo Gr 11 Sheets stockist confirms these physical values for drawing and design use.
Density
7.85 g/cm³
0.284 lb/in³
Melting Range
1420 – 1460°C
2590 – 2660°F approx
Modulus Of Elasticity
~190 GPa
At room temperature
Thermal Conductivity
~39 W/m·K
At 100°C
Coeff. Thermal Expansion
~13 µm/m·K
0-100°C approx
Specific Heat
~470 J/kg·K
Near room temperature
Recommended Max Service Temp
~600°C
Confirm exact limit via ASME Sec II Part D stress tables
Minimum Tempering Temp
620°C [1150°F]
Per ASTM A387 heat treatment clause
UNS K11789 Strips Equivalent Grades
One Chemistry, Several Nameplates
ASTM A387 Alloy Steel Gr 11 Sheets read the same 1.25Cr-0.5Mo-Si chemistry across each standard.
ASTM / ASME / UNS
- ASTM A387 Grade 11
- ASME SA387 Grade 11
- UNS K11789
EN / Werkstoff
- EN 10028-2 13CrMoSi5-5
- Werkstoff Nr. 1.7336
- Matches Silicon-Bearing K11789 Basis
JIS
- JIS SCMV3
- To JIS G4109 / D3543
- Confirmed On Order
Nearby ASTM Grades
- ASTM A387 Grade 12 (UNS K11757, Lower Si)
- ASTM A387 Grade 22 (2.25Cr-1Mo)
- ASTM A387 Grade 5 (5Cr-0.5Mo)
Forged & Pipe Cousins
- ASTM A182 Grade F11 (Flanges/Forgings)
- ASTM A335 Grade P11 (Pipe)
- ASTM A234 Grade WP11 (Fittings)
Indian Market Note
- No Single-Number IS Equivalent
- Ordered Directly As Gr 11 / K11789
- Compared By Chemistry & P-Number
Monthly Delivery of Alloy Steel Gr 11 Plate to Below Countries
| Export to | Countries | Continent | Ports | Shipping time |
|---|---|---|---|---|
 |
Saudi Arabia | Asia | Jubail | 7 |
 |
Italy | Europe | Genoa | 30 |
ASME SA387 Alloy Steel Gr 11 Sheets Surface Finish
Alloy Steel Gr 11 Sheets and plates leave our works ready for fabrication in the condition you specify.
Hot Rolled, Natural Finish
#4 Brushed Finish Plates
2B Cold Rolled Finish
#8 Mirror Polished Finish
Pickled & Oiled On Request
Shot Blasted & Primed
Bevelled Edges To Drawing
Profile / Laser Cut Blanks
Gr 11 Alloy Steel Chequered Plates Application Industries
1.25Cr-0.5Mo-Si chemistry suits welded pressure equipment across a wide industrial spread.
Refinery Pressure Vessels
Industrial & Power Plant Boilers
Heat Exchanger Shells
Oil & Gas Sour Service Equipment
Petrochemical Process Columns
Hydrocracker & Reactor Vessels
Fertiliser Plant Equipment
Storage Tanks For Hot Media
Alloy Steel ASTM A387 GR 11 Plates Weight Chart
Formula: Weight (kg/m²) = Thickness (mm) × 7.85. Multiply by actual plate area for total piece weight.
| Thickness (mm) | Weight (kg/m²) |
|---|---|
| 6 | 47.1 |
| 10 | 78.5 |
| 12 | 94.2 |
| 16 | 125.6 |
| 20 | 157.0 |
| 25 | 196.3 |
| 32 | 251.2 |
| 40 | 314.0 |
| 50 | 392.5 |
| 63 | 494.6 |
| 80 | 628.0 |
| 100 | 785.0 |
| 125 | 981.3 |
| 150 | 1177.5 |
Alloy Steel Gr 11 Plate Price In India
Driven Pricing, Not A Flat Rate Card
Alloy and ferro-molybdenum costs move weekly, so Gr 11 pricing follows daily references.
Send a thickness-wise size list for per-kg pricing. Get it inside 24 hours. HSN and GST are already worked out.
Alloy Steel Gr 11 Plate Delivered Weekly to the Following Countries
| Export to | Countries | Continent | Ports | Shipping time |
|---|---|---|---|---|
 |
UAE | Asia | Mina Rashid | 5 days |
 |
Thailand | Asia | Laem Chabang | 7 |
 |
Germany | Europe | Bremerhaven | 20 |
Stock, MOQ & Dispatch Timeline
From Enquiry To Gate Pass
The real clock on an Alloy Steel Gr 11 Plate order, not a marketing promise.
Day 0 – Enquiry
Mail thickness, class and quantity to our Mumbai desk
Day 1 – Driven Quote
Per-kg rate against the day’s alloy input reference, GST included
Day 2 – Inspection
Chemistry, mechanical and UT cleared, TPI called if needed
Day 3 – Dispatch
Stock sizes leave with LR copy and full document set
Stock Range
5 – 50mm
Common thicknesses held in Mumbai
Minimum Order
500 Kg
Per thickness, trial lots considered
Heavy Plate Lead Time
15 – 25 Days
Above 50mm, indented against order
Export Transit
Nhava Sheva
Air or sea, FOB CFR CIF DDP quoted
ASTM A387 Cr-Mo Gr 11 Cold Rolled Sheets Documentations
Every order ships with paperwork that matches the physical plate, heat for heat.
Mill Test Certificate
Chemical and mechanical results per EN 10204 3.1
Standard
EN 10204 3.2 Witnessed Certificate
SGS, BV, TUV or Lloyd’s, arranged on request
On Request
Ultrasonic Test Report
Per ASTM A435/A578 as applicable to thickness
On Request
Certificate Of Origin
Chamber-attested, needed for most export shipments
Export
Packing List & Invoice
Heat-number traceable listing for every bundle
Standard
Gr 11 Plate Testing & Inspection
We test every Alloy Steel Gr 11 Plate and Stainless Steel UNS K11789 Shim Sheet.
Chemical / PMI Analysis
Spectro reading against UNS K11789 composition limits
Hardness Test
Brinell readings recorded heat wise on every plate
Tensile & Yield Test
Tensile, yield and elongation tested per ASTM A370
Charpy Impact Test
V-notch impact at sub-zero temperature on request
Dimensional Inspection
Thickness, flatness and squareness checked to ASTM A6
Ultrasonic Testing
Internal soundness checked on plate above set thickness
Alloy Steel Gr 11 Plate Frequently Asked Questions
What type of material is SA 387 GR 11 Cl 2 Plate ?
Low-alloy 1.25Cr-0.5Mo-Si pressure vessel plate, UNS K11789, normalised & tempered class.
What is the equivalent of ASTM A387 Grade 11 steel Plate?
EN 10028-2 13CrMoSi5-5 (1.7336) and JIS SCMV3 are closest matches.
How much does a 1″ steel plate cost?
Price varies by class and quantity; send your thickness list for a quote.
What is the difference between Class 1 and Class 2 plate?
Same chemistry; Class 2 has higher tensile and yield through normalising & tempering.
What is the HSN code for Alloy Steel Gr 11 Plate?
HSN 7225 or 7226, taxed at 18% GST in India.
We Collaborate With Traders in the Following Cities
| Trading City | Trading City |
|---|---|
| Texas (USA) | California (USA) |
| Al Jubail (Saudi Arabia) | Dubai (UAE) |
| Dammam (Saudi Arabia) | Abu Dhabi (UAE) |
| Riyadh (Saudi Arabia) | Houston (USA) |
| Al Khobar (Saudi Arabia) | Indiana (USA) |
6 Reasons to choose Ganpat Industrial Corporation
- Distributor of Heat Exchanger parts and Alloys for High Temperature applications.
- Stockholder and importer of Ferrous and non ferrous metals.
- Wide stock of prime quality austenitic and Ferritic Stainless Steel for Extreme pressure environment.
- Marine grade steel at lowest price in Mumbai.
- Compare Price per KG in India and China.
- Offer Resale price to local suppliers, traders and wholesalers in UAE, Saudi Arabia, Egypt, and USA