ASTM / ASME / EN Certified

Alloy Steel Pipes & Tubes Manufacturer & Supplier in India

Unicorn Metal Industries is a premier Alloy Steel Pipes & Tubes Manufacturer in India, engineering high-performance piping for severe-service environments. Designed for refineries, chemical plants, and power facilities, our engineered alloys resist thermal fatigue, scaling, and mechanical stress where standard carbon steel fails.

As a leading Alloy Steel Pipes & Tubes Supplier in India, we secure mill-direct pricing on fully traceable, high-temperature seamless and welded piping. Every order comes complete with technical documentation, including MTCs, NACE compliance, and Third-Party Inspection (TPI) reports tailored to your blueprints. We stock certified Alloy Steel Pipes & Tubes in ASTM/ASME A335 specifications for high-pressure applications. Our ready inventory features ASTM A335 P1, P5, P9, P11, P12, P22, P23, and P91 Alloy Steel Pipes with complete heat traceability and mill test certificates to support your critical projects.

Request an Instant RFQ →

1/8″ NB to 24″ NBSize Range

P1 / P5 / P9 / P11 / P12 / P22 / P23 / P91Available Grades

Seamless / Welded / ERW / EFWManufacturing Types

ASTM A335 Alloy Steel Pipes and Tubes stocked by Manufacturer in India

Datasheet

Technical Specifications for Alloy Steel Pipes & Tubes

Specification Parameter	Technical Details
Standard Specifications	ASTM A335 / ASME SA335, ASTM A213 / ASME SA213
Material Grades	P1, P5, P9, P11, P12, P22, P23, P91
Outer Diameter (OD)	1/8" NB to 24" NB (Seamless), Up to 60" (Welded/EFW)
Wall Thickness / Schedule	SCH 20, SCH 30, SCH 40, STD, SCH 80, XS, SCH 160, XXS
Form & Types	Seamless, Welded, ERW, EFW, Honed, Hydraulic Tubes
Quality Documentation	MTC (EN 10204 3.1 / 3.2), NACE MR0175/MR0103, TPI Clearance

Grade Selection & Technical Overview

Choosing the right grade of ASTM A335 Alloy Steel Pipes & Tubes prevents thermal fatigue and operational downtime. Unicorn Metal Industries supplies mill-certified, ready-to-ship stock tailored to your exact pressure and temperature requirements:

Grade	Primary Specs	Key Features	Main Applications
Low Alloy	P1, P11, P12	Moderate heat resistance; easy to weld	Steam lines & heat exchangers
Mid Alloy	P5, P9	High-chromium; resists corrosion	Refineries & furnace piping
Heavy Duty	P22, P23	High creep strength under pressure	Boiler tubes & superheaters
Supercritical	P91	Max yield strength & fatigue resistance	High-temp power plant loops

Selecting the correct grade prevents premature thermal fatigue and ensures full compliance with international safety standards. All available options can be custom-cut and supplied with complete heat traceability to meet your exact engineering requirements. As a leading Alloy Steel Pipes & Tubes Manufacturer in India, all our products are custom-cut to size and delivered with full EN 10204 3.1 MTC heat traceability.

Request Instant Wholesale Quote

Chemical Composition Analysis

SHEET 02

Element / Requirement	Grade P5	Grade P9	Grade P11	Grade P22	Grade P91
UNS Designation	K41545	S50400	K11597	K21590	K91560
Carbon (%)	0.15 max	0.15 max	0.05 – 0.15	0.05 – 0.15	0.08 – 0.12
Chromium (%)	4.00 – 6.00	8.00 – 10.00	1.00 – 1.50	1.90 – 2.60	8.00 – 9.50
Molybdenum (%)	0.45 – 0.65	0.90 – 1.10	0.44 – 0.65	0.87 – 1.13	0.85 – 1.05

Mechanical & Tensile Properties

SHEET 03

Property / Requirement	Grade P5	Grade P9	Grade P11	Grade P22	Grade P91
Tensile Strength, Min (ksi)	60	60	60	60	85
Tensile Strength, Min (MPa)	415	415	415	415	585
Yield Strength, Min (ksi)	30	30	30	30	60
Yield Strength, Min (MPa)	205	205	205	205	415
Hardness Limit	—	—	—	—	Max 250 HB / 265 HV

These comprehensive specifications ensure that ASTM A335 Alloy Steel Pipes & Tubes deliver reliable performance across demanding thermal and pressure applications. Precise alloying ensures post-weld stability and long-term structural integrity in critical infrastructure systems.

Applications

Practical Applications of Alloy Steel Pipes & Tubes

These high-performance alloy profiles resist thermal creep and extreme pressure, making them ideal for heavy-duty energy environments. They are widely implemented across several core sectors for critical infrastructure and industrial systems.

APP / 01

Power Generation & Boiler Units

ASTM A335 P11 / P22 used for main steam lines, superheater coils, reheater tubes, and pressure distribution headers.

APP / 02

Petrochemical Refineries & Processing

ASTM A335 P5 / P9 essential in hydrocrackers, catalytic cracking units (FCCU), and high-temp furnace piping.

APP / 03

Supercritical Power Infrastructure

ASTM A335 P91 preferred for high yield strength in ultra-high temperature steam loops and advanced power systems.

APP / 04

Heavy Engineering & Heat Exchangers

ASTM A335 P1 / P12 / P23 applied in pressure vessels, shell assemblies, and industrial boiler systems.

Alloy Steel Pipes Industrial Applications

Quality Assurance

Quality Testing Protocols & Certified Credentials

To ensure complete reliability on site, our steel products undergo rigorous quality checks prior to dispatch:

Certificate / Test Type	Purpose & Safety Utility
ISO 9001:2015 Certification	Confirms strict, quality-controlled manufacturing processes throughout production.
EN 10204 3.1 Mill Test Report (MTC)	Verifies exact chemical breakdown and mechanical strength tests with complete heat code traceability.
Non-Destructive Testing (NDT)	Includes Hydrostatic testing and Ultrasonic testing to ensure zero leaks or structural defects.
NACE MR0175/MR0103 Compliance	Certifies suitability for sour service and hydrogen embrittlement resistance for critical applications.
Government & Export Clearances	Fully compliant with Indian trade regulations and international export norms for unrestricted global deployment.

View & Download Our Full-Resolution Quality Certificates

FAQ

Frequently Asked Questions

What makes ASTM A335 alloy steel pipes suitable for high-temperature service?

Chromium and molybdenum additions provide exceptional resistance to thermal oxidation, creep deformation, and structural degradation under extreme heat cycles. These elements ensure long-term microstructural stability at elevated temperatures.

What is the main difference between ASTM A335 P11, P22, and P91 grades?

The primary difference lies in chromium and vanadium content. Grade P11 suits medium thermal service with moderate creep strength, P22 offers higher creep strength for boiler applications, and P91 provides elite performance for supercritical operations with maximum yield strength.

Can ASTM A335 alloy steel pipes be welded on site?

Yes. These grades support standard field welding procedures when combined with proper pre-heating and post-weld heat treatment (PWHT) parameters. Proper welding technique is critical to maintain heat-affected zone properties.

Are ERW and Seamless alloy steel pipes different in pressure rating?

Seamless alloy pipes are extruded without a weld seam, offering higher uniform pressure ratings and reliable performance under heavy cyclic stress. ERW pipes, when properly manufactured, provide excellent service at specified pressure limits.

Why source directly from an Indian alloy steel pipe manufacturer?

Direct factory sourcing eliminates middleman markups, gives you access to custom cut lengths, and guarantees authentic mill test certificates with full heat traceability. You also benefit from rapid dispatch and direct technical support.

What documents are included with each shipment?

Every shipment includes EN 10204 3.1 Mill Test Reports (MTC) confirming chemical composition and mechanical properties, NACE compliance certifications where applicable, and Third-Party Inspection clearances for critical applications.

Request a Technical Sourcing Quote

Sourcing directly from an established factory pairs certified material quality with competitive project pricing. Whether you need bulk shipments or custom wall thicknesses, our team provides instant pricing, technical guidance, and reliable dispatch schedules for critical infrastructure projects.

📞 Get Factory-Direct Pricing