1. Austenitic Stainless Steels (300 Series):
• 304 (A2): Ideal for general use, used in many applications such as the food industry, chemical industry, and household items.

• 316 (A4): Resistant to seawater and aggressive chemicals, used in applications like shipbuilding, chemical industry, and medical devices.

• 321: Known for high-temperature resistance and weldability, preferred in the automotive and aerospace industries.

2. Ferritic Stainless Steels (400 Series):
• 430: High corrosion resistance, often used in kitchen utensils, automotive exhaust systems, and supermarket shelves.

3. Martensitic Stainless Steels (400 Series):
• 410: Offers high strength and hardness, used in applications like toolmaking, bearings, and valves.

4. Duplex Stainless Steels (200 and 2205):
• 2205: Offers high corrosion resistance and strength, preferred in challenging conditions like the maritime, oil, and gas industries.

5. Nickel Alloys:
• Inconel 600 and 625: Known for high-temperature and corrosion resistance, used in the chemical industry, nuclear energy, and aerospace.

6. Hastelloy Alloys:
• Hastelloy C276: Used in corrosive environments for chemical processes, maritime, and petrochemical industries.

The selection of stainless steel pipe grade should be based on the specific requirements of an application and the environmental conditions. Each grade has its advantages and limitations, so choosing the right material is crucial.