Stainless Steel - Grade 305 (UNS S30500)
Stainless steel was a miraculous invention. It changed the way many industries work. With its incredible corrosion resistance, durability, and strength, it has found its way into multiple processes across various industries. Owing to its numerous use cases, various variations were done to the chemical composition of stainless steel to form different grades.
In this article, we will read about one such prominent stainless steel; UNS S30500 or SS grade 305.
About Grade 305 Stainless Steel - Grade 305
Grade 305 is an austenitic chromium-nickel alloy steel grade. Due to its lower strength and work hardening rate, it can be easily formed and deeply drawn into complex structures. SS grade 305 shows high non-magnetism and excellent corrosion resistance. It is commonly used in industrial and domestic applications, such as heat exchangers, pipes and valves. It is also suitable for applications that require high corrosion resistance.
AISI - Grade 305 Chemical Composition
Let’s start with the most important aspect of grade 305 stainless steel, its chemical composition. It is its chemical composition that imparts it with its unique properties. AISI 305 contains a good amount of chromium and nickel making it highly corrosion resistant, strong, and temperature tolerance.
| Element | Percentage |
| Iron, Fe | 67% |
| Chromium, Cr | 18% |
| Nickel, Ni | 12% |
| Manganese, Mn | ≤ 2% |
| Silicon, Si | ≤ 1% |
| Carbon, C | 0.12% |
| Phosphorous, P | 0.045% |
| Sulfur, S | 0.030% |
Physical Properties
Considering the physical properties of stainless steel is the key element in deciding its use in various applications. If you are considering SS grade 305 for your application, have a look at its physical properties and check if they align with your use case.
| Property | Value |
| Density | 8 g/cm³ |
| Melting point | 1454°C |
Mechanical Properties
Apart from the physical properties, it is crucial to understand and analyze the mechanical properties of UNS S30500 including hardness, tensile strength, yield strength, and elongation. Knowing the properties of the material will help you determine if it is suitable for use in your application.
| Property | Value |
| Tensile strength, ultimate | 585 MPa |
| Tensile strength, yield (@ 0.2%) | 260 MPa |
| Modulus of elasticity | 193 GPa |
| Shear modulus | 86 GPa |
| Elongation at break (in 50 mm) | 50% |
| Hardness, Brinell | 80 |
| Hardness, Knoop (converted from Brinell) | 97 |
| Hardness, Rockwell B (converted from Brinell) | 45 |
| Hardness, Vickers (converted from Brinell) | 82 |
Thermal Properties
If you need an ideal element to bear extreme temperatures, then it becomes crucial to know about its thermal properties. Let us go through the thermal properties of SS grade 305, to know its performance in extreme temperatures.
| Property | Value |
| Thermal expansion coefficient (@ 0–100°C/32–212°F) | 17.3 µm/m°C |
| Thermal conductivity (@ 0–100°C/32–212°F) | 16.3 W/mK |
Applications
The following are the major applications of grade 305 stainless steel:
- Spun or deep-drawn eyelets
- Barrels
- Shells
- Cold-headed rivets or screws
Frequently Asked Questions
Q1. What is 305 stainless steel used for?
305 stainless steel is used for spun or deep-drawn eyelets, barrels, shells, and cold-headed rivets or screws, as well as heat exchangers, pipes, and valves in industrial and domestic applications.
Q2. Why is 305 stainless steel preferred for deep drawing?
305 stainless steel has a lower strength and work-hardening rate than other austenitic grades like 304, which means it resists hardening during forming. This allows it to be drawn into deep, complex shapes without cracking or requiring frequent intermediate annealing.
Q3. What is the difference between 305 and 304 stainless steel?
305 stainless steel has a higher nickel content than 304, which lowers its work-hardening rate and makes it better suited to deep drawing and heavy forming operations. 304 is more commonly used as a general-purpose structural and fabrication grade.
Q4. What is the UNS number for 305 stainless steel?
The UNS designation for 305 stainless steel is S30500.