Stainless Steel Grades 304 vs 316 vs 430- Explained 

TL;DR: Choosing the right grade of stainless steel depends on your operating environment and structural requirements. Grade 304 suits general industrial use. Grade 316 adds molybdenum for marine and chemical environments. Grade 430 is a cost-effective magnetic alternative for indoor applications. This guide matches each grade to its application using IS and ASTM references.

Grade selection in stainless steel is not an aesthetic decision — it is a structural and chemical one. The wrong grade in a corrosive or high-moisture environment leads to early failure, costly replacement, and supply chain disruption. India’s industrial buyers across food processing, pharmaceuticals, chemicals, and infrastructure specify stainless steel by grade — not by appearance. This guide covers the three most widely procured grades of stainless steel, their IS and ASTM references, mechanical properties, and how to match grade to application.

What Is Stainless Steel?

Stainless steel is a chromium-containing iron alloy with a minimum chromium content of 10.5% by mass, as defined under IS 6911 and ASTM A240. The chromium forms a passive oxide layer on the surface that resists corrosion without requiring external coating or treatment.

This self-healing oxide layer distinguishes stainless steel from plain carbon steel and mild steel. When scratched or cut, the chromium oxide layer reforms on exposure to oxygen. This property makes stainless steel suitable for applications where surface integrity and corrosion resistance are critical over long service lives.

The composition of stainless steel varies by grade. Beyond chromium, manufacturers add nickel to improve ductility and corrosion resistance in acidic environments. Molybdenum is added to resist chloride attack. Manganese improves high-temperature strength. The combination and proportion of these elements define the grade — and therefore the performance.

Standard carbon steel corrodes when iron reacts with oxygen and moisture. Stainless steel’s chromium content interrupts this reaction. This makes it the material of choice across Indian industries where hygiene, chemical exposure, or outdoor environments are factors.

Read in detail about Stainless Steel

Classification of Stainless Steel: The Grade Families

The classification of stainless steel follows a family structure based on crystalline microstructure. Each family has distinct mechanical and chemical properties that determine its industrial suitability.

Three families cover the grades most commonly procured in Indian industry:

Austenitic (300 Series): The most widely used grades of stainless steel globally. High chromium and nickel content makes these grades non-magnetic and highly resistant to corrosion. They are weldable, formable, and suitable for food-grade, pharmaceutical, and chemical applications. Grade 304 and Grade 316 are both austenitic.

Ferritic (400 Series): Chromium-based grades with very little or no nickel. Ferritic grades are magnetic and more cost-effective than the 300 series. They offer good corrosion resistance in mild environments but are not suitable for marine or high-chloride conditions. Grade 430 is ferritic.

Martensitic: High-carbon grades used where hardness is the primary requirement — cutting tools, turbine blades, and surgical instruments. Not typically specified for structural or fabrication applications.

Family	Series	Magnetic?	Nickel Content	Typical Grades
Austenitic	300	No	High (8–10%)	304, 316
Ferritic	400	Yes	Low (<1%)	430
Martensitic	400	Yes	Low	410, 420

Mechanical Properties of Stainless Steel: Grade Comparison

The mechanical properties of stainless steel determine load-bearing capacity, formability, weldability, and long-term performance under stress. These properties vary significantly across grades and must be verified via mill test reports at procurement stage.

Property	Grade 304	Grade 316	Grade 430
Min. Tensile Strength	515 MPa	515 MPa	450 MPa
Min. Yield Strength	205 MPa	205 MPa	205 MPa
Min. Elongation	40%	40%	22%
Hardness (Brinell)	≤201 HB	≤217 HB	≤183 HB
Weldability	Excellent	Excellent	Moderate
Magnetic	No	No	Yes

Values per ASTM A240 / IS 6911. Confirm against current mill test certificate for each consignment.

Grade 430 has lower elongation and reduced weldability compared to austenitic grades. This limits its use in applications requiring complex forming or site welding. For structural and fabrication applications in Indian industry, Grade 304 and Grade 316 are the standard specifications.

SS Material Composition: Grades Stainless Steel Chart

The chemical composition of each stainless steel grade determines its corrosion resistance, weldability, and cost. All three grades are defined under ASTM A240 and covered by IS 6911 for Indian procurement.

Grade	Chromium	Nickel	Molybdenum	Carbon (Max)	Magnetic
304	18%	8%	0%	0.08%	No
316	16%	10%	2.0–3.0%	0.08%	No
430	16%	<0.75%	0%	0.12%	Yes

This stainless steel grades chart is a procurement reference. Confirm exact composition limits against the applicable ASTM or IS standard edition and the supplier’s mill test report.

The defining difference in 316 stainless steel composition is the 2.0–3.0% molybdenum addition. No other element in the standard austenitic grade family provides equivalent resistance to chloride-induced pitting. This is why 316 stainless steel commands a price premium over 304 — and why substituting 304 for 316 in marine or chemical environments is a procurement and engineering error.

Grade 304: The Industrial Standard

Grade 304 is the most widely procured stainless steel grade in Indian industry. It contains 18% chromium and 8% nickel — the “18/8” composition — and meets ASTM A240 and IS 6911 requirements for general industrial use.

Grade 304 resists oxidising acids, most food-grade chemicals, and atmospheric corrosion in standard industrial environments. It is weldable by all common methods and formable into sheets, coils, pipes, and precision components.

Applications: Food processing equipment, kitchen and catering infrastructure, storage tanks, architectural facades, industrial piping, chemical vessels in non-chloride environments.

Limitation: Grade 304 is susceptible to pitting corrosion in chloride environments — coastal locations, saltwater contact, and chloride-heavy cleaning agents. For these applications, Grade 316 is the correct specification.

Indicative pricing for Grade 304 stainless steel sheet: ₹180–₹220 per kg (ex-warehouse, Mumbai, indicative as of October 2026, subject to market conditions). Contact OFB for current pricing.

Grade 316 Stainless Steel: The Marine and Chemical Grade

316 stainless steel is the correct specification wherever chloride exposure, marine environments, or industrial chemical processing are factors. Its composition — 16% chromium, 10% nickel, and 2.0–3.0% molybdenum — provides chloride resistance that Grade 304 cannot match.

The molybdenum in 316 stainless forms a protective barrier against pitting and crevice corrosion in chloride-rich environments. This makes it the standard grade for coastal infrastructure, offshore equipment, pharmaceutical processing, and chemical plant fabrication.

Applications: Marine hardware and offshore structures, pharmaceutical and food-grade processing equipment, chemical storage vessels, surgical instruments, desalination plant components, coastal architectural installations.

Cost factor: 316 stainless steel commands a premium over 304 — typically 20–30% higher on a per-kg basis — because of its higher nickel content and the molybdenum addition. In environments where chloride corrosion is a genuine risk, this premium is significantly less than the cost of early structural failure and replacement.

Indicative pricing for 316 stainless steel sheet: ₹220–₹270 per kg (ex-warehouse, Mumbai, indicative as of October 2026, subject to market conditions). Contact OFB for current pricing.

Grade 430: The Cost-Effective Ferritic Option

Grade 430 is a ferritic stainless steel with 16% chromium and minimal nickel. It is the cost-effective specification for indoor and low-moisture applications where chloride exposure is not a factor.

Grade 430’s magnetic property makes it easy to identify at warehouse and site level — a standard magnet will adhere to 430 but not to 304 or 316. This is a practical field check when verifying material identity before fabrication.

Applications: Indoor automotive trim, domestic appliances, decorative architectural elements, catering equipment in low-moisture environments, elevator interiors.

Limitations: Grade 430 has lower elongation than austenitic grades, which limits complex forming operations. It is more difficult to weld than 304 or 316 and does not perform at the same level in outdoor or coastal environments.

Indicative pricing for Grade 430 stainless steel sheet: ₹130–₹160 per kg (ex-warehouse, Mumbai, indicative as of October 2026, subject to market conditions). Contact OFB for current pricing.

How to Procure Stainless Steel by Grade: A Procurement Checklist?

Step 1 — Define the Operating Environment
Identify whether the application involves chloride exposure, high moisture, food contact, chemical processing, or standard indoor use. This single factor determines whether the specification is 304, 316, or 430. Do not leave grade selection to the supplier.

Step 2 — Specify Grade with Standard Reference
State grade and applicable standard at order placement: “Grade 304 per ASTM A240” or “Grade 316 per IS 6911.” Grade numbers without standard references allow suppliers to substitute equivalent or inferior material.

Step 3 — Specify Product Form, Thickness, and Surface Finish
Stainless steel is procured as sheets, coils, pipes, bars, or structural sections. Each form has its own thickness tolerances and surface finish designations (2B, BA, No. 4, No. 8). Specify all three at order stage — grade, form, and finish.

Step 4 — Request Mill Test Certificates
MTCs confirm the chemical composition and mechanical properties of stainless steel for the specific batch. Verify chromium, nickel, and molybdenum content against the grade specification. For 316, confirm molybdenum is within the 2.0–3.0% range.

Step 5 — Verify with a Field Check on Delivery
Use a magnet to verify austenitic vs ferritic material on arrival. 304 and 316 are non-magnetic — a magnet will not adhere. Grade 430 is magnetic. This does not replace MTC verification but catches obvious grade substitution errors before fabrication begins.

What Determines Grades of Stainless Steel Prices in India?

Stainless steel prices in India are driven by three primary input cost variables: global nickel prices, molybdenum prices, and domestic scrap and ferro-alloy costs.

Nickel is the largest price driver for 300-series grades. Global nickel prices — tracked on the London Metal Exchange (LME) — directly affect 304 and 316 pricing in Indian markets. When nickel prices rise, 316 stainless steel is disproportionately affected because of its higher nickel content.

Molybdenum adds a secondary premium to 316 stainless steel pricing above 304. Molybdenum is a relatively low-volume metal globally, and supply-side changes create price volatility in 316 that 304 does not experience.

Grade 430 pricing is less volatile than 300-series grades because it contains negligible nickel and no molybdenum. Its price tracks primarily with chromium and scrap steel indices.

Regional variation affects delivered pricing in India. Mumbai and Ahmedabad are the primary stainless steel trading hubs. Buyers in South and East India pay logistics premiums on top of hub pricing.

Grades of stainless steel in India follow global LME movements with a 2–4 week lag through the import and distribution chain. Procurement teams buying in volume benefit from tracking LME nickel as a forward indicator of domestic stainless steel pricing.

How to Source Stainless Steel Through OFB?

OfBusiness (OFB), India’s largest B2B industrial procurement platform, connects MSME manufacturers, fabricators, and industrial buyers with verified stainless steel suppliers across the 304, 316, and 430 grade range.

OFB’s steel category covers stainless steel sheets, coils, pipes, and structural sections in standard industrial grades. All suppliers on OFB’s platform undergo quality and compliance verification. Mill Test Certificates are available at point of order — confirming grade, composition, and mechanical properties per ASTM A240 or IS 6911.

Grade-specific sourcing: OFB allows buyers to specify 316 stainless steel separately from 304 — not as a substitutable alternative. This removes the grade-mixing risk that occurs in traditional spot-buy supply chains.

Procurement credit through Oxyzo: Large stainless steel orders can be financed through Oxyzo Financial Services, OFB’s RBI-registered NBFC partner. The credit facility is procurement-linked — activated at point of order on the OFB platform. This preserves working capital for fabricators and manufacturers with long production cycles. This is not a standalone loan product.

Logistics support: OFB provides logistics coordination for stainless steel orders across India. Delivery timelines depend on order volume, product form, and logistics partner availability.

Conclusion

Grade selection in stainless steel procurement comes down to one question: what environment will the material operate in? Grade 304 covers most standard industrial and food-grade applications. 316 stainless steel is the correct specification wherever chlorides, marine conditions, or chemical processing are present. Grade 430 serves cost-sensitive indoor applications where austenitic performance is not required. Specify grade with the applicable ASTM A240 or IS 6911 reference at order stage, request MTCs for every consignment, and verify mechanical properties of stainless steel before fabrication begins. Source verified stainless steel across all three grades on OFB, or register as a buyer to request grade-specific pricing.