Table of Contents
1. Introduction
When industries demand a stainless steel grade that offers superior heat resistance, excellent strength, and reliable performance, Stainless Steel 321 Grade Sheet becomes a preferred choice. Engineered with titanium stabilization, SS 321 sheets are widely used in aerospace, petrochemical, automotive, and power generation industries.
This blog will cover everything you need to know about Stainless Steel 321 Grade Sheets, including thickness, available sizes, tolerance limits, composition, and key applications.
2. What is Stainless Steel 321 Grade Sheet?
Stainless Steel 321 is an austenitic stainless steel alloy stabilized with titanium. This stabilization prevents carbide precipitation during welding and ensures excellent resistance to intergranular corrosion.
Unlike SS 304, Stainless Steel 321 performs better in high-temperature environments (up to 870°C continuous exposure).
In simple terms, SS 321 sheets are heat-resistant, weldable, and durable materials used where long-term performance is crucial.
3. Chemical Composition of SS 321 Sheet
| Element | Percentage (%) |
|---|---|
| Chromium (Cr) | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 12.0 |
| Titanium (Ti) | ≥ 0.70 |
| Carbon (C) | ≤ 0.08 |
| Manganese (Mn) | ≤ 2.0 |
| Silicon (Si) | ≤ 1.0 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.03 |
| Iron (Fe) | Balance |
Why this matters:
- Titanium prevents carbide precipitation during welding.
- Chromium + Nickel improves corrosion and oxidation resistance.
4. Stainless Steel 321 Sheet Thickness & Sizes
SS 321 Grade Sheets are available in a wide range of thicknesses and dimensions to suit different industrial requirements.
Standard Thickness Range:
- 0.3 mm to 120 mm
Common Sizes Available:
- 1000 mm x 2000 mm
- 1250 mm x 2500 mm
- 1500 mm x 3000 mm
- Custom cut-to-size sheets available on request
Thinner sheets are used in automotive and aerospace applications, while thicker plates are used in boilers, pressure vessels, and heat exchangers.
5. Tolerance Standards for SS 321 Grade Sheet
Tolerance refers to the permissible deviation in sheet thickness, width, and flatness as per international standards.
- Thickness Tolerance (as per ASTM A240): ±0.02 mm to ±0.10 mm (depending on gauge)
- Width Tolerance: ±2 mm to ±5 mm
- Length Tolerance: ±5 mm
- Flatness Tolerance: As per ASTM & ASME standards
These tolerances ensure that the SS 321 grade sheet fits precisely into fabrication and assembly requirements without the need for excess machining.
6. Key Properties of Stainless Steel 321 Sheets
- High Heat Resistance – performs well up to 870°C.
- Oxidation Resistance – stable under continuous high-temperature exposure.
- Excellent Weldability – titanium prevents carbide precipitation.
- Durable and Strong – maintains tensile strength even at high temperatures.
- Corrosion Resistant – resists acids, alkalis, and scaling.
7. Applications of SS 321 Grade Sheets
Stainless Steel 321 Grade Sheets are widely used in:
- Aerospace Industry – jet engine parts, exhaust systems.
- Petrochemical Plants – refinery piping, catalytic equipment.
- Power Generation – heat exchangers, boilers, superheater tubes.
- Automotive Industry – exhaust systems, manifolds.
- Food Processing – sterilizers and heat treatment trays.
- Furnace Equipment – radiant tubes, conveyors, kilns.
Stainless Steel 321 Grade Sheets are a high-performance material trusted for their strength, corrosion resistance, and precision tolerances. With a wide range of thicknesses and sizes, these sheets serve industries that demand reliability under extreme conditions, from aerospace and automotive to petrochemical and power generation.
At Riyaarth Overseas, we provide premium-quality Stainless Steel 321 Grade Sheets manufactured to global standards. Our products come in various sizes, thicknesses, and tolerances, ensuring you get the right material for your specific application. Contact us today for bulk or customized orders.