Steel House India is a premier manufacturer, supplier, and stockist of high-performance ASTM A276 AISI 431 stainless steel round bars in India. Engineered as a high-strength, hardenable martensitic stainless steel, Grade 431 (UNS S43100) is specifically formulated to retain excellent mechanical properties, superior torque capability, and reliable corrosion resistance in demanding industrial environments. With a high chromium content ranging from 15% to 17%, this grade is the preferred choice for engineering components that require a perfect balance of toughness, hardness, and wear resistance. By combining precise chemical refinement with advanced heat treatment capabilities, we ensure our AISI 431 bars deliver the structural integrity required for critical components subjected to high-stress industrial conditions.
Our comprehensive inventory is meticulously sourced from premium VOD/AOD refined billets to ensure metallurgical purity and long-term reliability. While our expertise in Grade 431 is unmatched, we maintain a robust supply chain for various other industrial grades to meet your specific design parameters, including the versatile AISI 304 Stainless Steel Round Bar for general structural use, and the corrosion-resistant AISI 316L Stainless Steel Round Bar for specialized chemical processing requirements. With our centralized distribution hub in Mumbai, we provide pan-India delivery, ensuring that your procurement needs—from prototype development to large-scale infrastructure projects—are met with precision, competitive pricing, and industry-leading lead times.
Bulk 431 Stock
Precision Cut Bars
Ready-Stock 431 Inventory
Chemical Composition of AISI 431
| Element | Percentage (%) |
|---|---|
| Carbon (C) | 0.12 – 0.20 |
| Chromium (Cr) | 15.00 – 17.00 |
| Nickel (Ni) | 1.25 – 2.50 |
| Manganese (Mn) | 1.00 Max |
| Silicon (Si) | 1.00 Max |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength (Min) | 850 – 1000 MPa |
| Yield Strength (0.2% Offset) | 600 – 700 MPa |
| Elongation | 12% – 15% |
| Hardness (Brinell) | 248 – 302 HB |
Specifications
Standards: ASTM A276, ASTM A479, ASME SA276.
Grade Equivalent: UNS S43100, WNR 1.4057, X17CrNi16-2.
Testing: PMI, Ultrasonic, Hardness, and Tensile testing.
Documentation: EN 10204 3.1 Mill Test Certificate (MTC).
Size Range
We offer an extensive, ready-to-dispatch inventory:
Round Bar: 4mm to 500mm diameter.
Hex/Square Bar: 18mm to 60mm.
Custom Sizes: Precision cutting and processing available per your
drawings.
Equivalent Grades
| Standard | Designation |
|---|---|
| USA (AISI) | 431 |
| Germany (DIN) | 1.4057 |
| Europe (EN) | X17CrNi16-2 |
| Japan (JIS) | SUS 431 |
Grade Comparison
Selecting the optimal stainless steel grade is critical for balancing mechanical strength with environmental resistance. Comparing AISI 431 with standard austenitic grades helps ensure your component choice aligns perfectly with temperature, stress, and corrosion-resistance design parameters.
| Feature | Grade 431 | Grade 316L | Grade 304 |
|---|---|---|---|
| Classification | Martensitic | Austenitic | Austenitic |
| Corrosion Resistance | Moderate | Excellent | Good |
| Hardness | High | Low | Low |
| Strength | Very High | Moderate | Moderate |
When your project demands superior resistance in aggressive chemical or marine environments, procurement teams often evaluate the high-molybdenum content of AISI 316L Stainless Steel Round Bar, which provides enhanced pitting resistance. For general-purpose infrastructure where cost-effectiveness and formability are prioritized, the globally standardized AISI 304 Stainless Steel Round Bar remains the benchmark for versatility.
Applications
■ Marine Engineering: Propeller shafts, pump shafts, and marine
hardware.
■ Aerospace: High-strength structural bolts and critical aircraft
components.
■ Chemical Processing: Valve components, agitator shafts, and
refinery hardware.
■ General Engineering: Industrial machinery requiring high torque and
wear resistance.
Advantages & Features
■ High Tensile Strength: Optimized for load-bearing and torque-heavy
applications.
■ Superior Hardness: Fully hardenable through heat treatment for
wear-intensive applications.
■ Corrosion Resistance: Offers better resistance than standard 410
grade.
■ Ease of Machining: Good machinability in the annealed condition.
Pricing & Stock Availability
Starting Price: ₹160 – ₹340/Kg (subject to current market rates, size, quantity, and alloy surcharges).
📊 Request an Instant Commercial Quote: Metal market pricing fluctuates based on daily raw chromium, nickel, and alloy surcharges. Our commercial team adapts quotes dynamically to offer you the best value based on order tonnage and custom processing requirements. Contact our Mumbai sales office today for a real-time bulk contract quotation.
Why Choose Steel House India
As a leading manufacturer, stockist, and supplier in Mumbai, we streamline
the procurement process for industrial buyers across India:
■ Ready Stock: Minimize your downtime with our extensive,
immediately available inventory.
■ Material Authenticity: 100% traceability with EN 10204 3.1
certification.
■ Pan-India Logistics: Rapid, secure transit to your site,
regardless of your industrial location.
■ Technical Excellence: Our team provides expert guidance on
material selection and heat treatment compatibility.
Frequently Asked Questions (FAQ)
1. What is the primary use of AISI 431 stainless steel?
AISI 431 is primarily used for high-torque mechanical applications, such as marine propeller shafts, pump shafts, and aerospace fasteners, where both high tensile strength and moderate corrosion resistance are required.
2. Why is AISI 431 considered a "hardenable" stainless steel?
Unlike standard austenitic grades, AISI 431 is a martensitic stainless steel. This means it contains a specific carbon-chromium balance that allows it to be heat-treated (quenched and tempered) to achieve significantly higher hardness and mechanical strength.
3. How does AISI 431 compare to AISI 304 in terms of strength?
AISI 431 offers much higher tensile strength and hardness than AISI 304. While 304 is better for general corrosion resistance, 431 is the superior choice for load-bearing and wear-intensive industrial components.
4. Is AISI 431 resistant to seawater corrosion?
Yes, AISI 431 is widely recognized for its ability to perform well in marine environments. Its 15-17% chromium content provides the necessary resistance to oxidation and mild saline corrosion found in marine pump and shaft applications.
5. What are the common difficulties in welding AISI 431?
As a martensitic grade, AISI 431 is prone to cracking during welding due to its high hardenability. It requires specific pre-heating and post-weld heat treatment protocols to maintain structural integrity.
6. Does Steel House India provide MTC with 431 round bars?
Yes, we provide an EN 10204 3.1 Mill Test Certificate with every shipment, ensuring complete traceability of chemical composition and mechanical properties for your project compliance.
7. Is AISI 431 magnetic?
Yes, AISI 431 is strongly magnetic in all conditions. This is a characteristic property of its martensitic crystalline structure.
8. What determines the price of AISI 431 per kg?
The price is determined by the current LME (London Metal Exchange) base rates for nickel and chromium, the specific diameter of the bar, the quantity ordered, and any custom processing or heat treatment requirements.
Request a Callback from Our Sourcing Desk
This commercial product page is managed by Steel House India. For immediate product inquiries, direct bulk contracts, or to request a technical consultation, please forward your detailed material requirements to sales@steelhouseindia.com. Once received, a senior technical sourcing officer will review your specifications and contact you within two business hours to finalize your order.