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Technical Specifications
Product Overview
303 Stainless Steel Round Bar is a free-machining austenitic stainless steel that contains sulfur and phosphorus additions to improve machinability. This grade offers excellent machining characteristics while maintaining good corrosion resistance, making it ideal for precision components and high-volume production applications.
Key Features:
- Excellent machinability - 78% rating compared to 1212 carbon steel
- Good corrosion resistance in mild environments
- Non-magnetic in annealed condition
- Superior surface finish capabilities
- Ideal for automatic screw machine operations
Manufacturing Process: Produced through hot rolling followed by cold drawing or peeling to achieve precise dimensions and superior surface finish. Heat treated to annealed condition for optimal machinability.
Applications: Precision machined components, screws, bolts, nuts, shafts, fittings, valve components, pump parts, aircraft fittings, and automatic screw machine products where excellent machinability is required.
🧪 Chemical Composition
| Element | Min % | Max % | Typical % | ASTM A582 Requirement |
|---|---|---|---|---|
| Carbon (C) | - | 0.15 | 0.10 | ≤ 0.15 |
| Chromium (Cr) | 17.0 | 19.0 | 18.0 | 17.0-19.0 |
| Nickel (Ni) | 8.0 | 10.0 | 9.0 | 8.0-10.0 |
| Manganese (Mn) | - | 2.00 | 1.50 | ≤ 2.00 |
| Silicon (Si) | - | 1.00 | 0.60 | ≤ 1.00 |
| Phosphorus (P) | - | 0.20 | 0.15 | ≤ 0.20 |
| Sulfur (S) | 0.15 | 0.35 | 0.25 | 0.15-0.35 |
| Lead (Pb) | - | 0.20 | 0.10 | ≤ 0.20 |
| Iron (Fe) | Balance | Balance | 69.4 | Balance |
⚙️ Mechanical Properties
| Property | ASTM Requirement | Typical Value | Test Method | Temperature |
|---|---|---|---|---|
| Tensile Strength | 515 MPa min | 620 MPa | ASTM A370 | Room Temp |
| Yield Strength (0.2%) | 205 MPa min | 275 MPa | ASTM A370 | Room Temp |
| Elongation | 35% min | 40% | ASTM A370 | Room Temp |
| Hardness (Brinell) | 201 HB max | 185 HB | ASTM E10 | Room Temp |
| Hardness (Rockwell B) | 92 HRB max | 88 HRB | ASTM E18 | Room Temp |
| Modulus of Elasticity | - | 200 GPa | ASTM E111 | Room Temp |
| Impact Energy (Charpy V) | - | 150+ J | ASTM E23 | Room Temp |
🔬 Physical Properties
| Property | Value | Unit | Temperature | Test Standard |
|---|---|---|---|---|
| Density | 8.03 | g/cm3 | 20°C | ASTM B311 |
| Melting Point | 1400-1420 | °C | - | DSC Analysis |
| Thermal Conductivity | 16.3 | W/m·K | 100°C | ASTM E1461 |
| Specific Heat | 500 | J/kg·K | 0-100°C | ASTM C351 |
| Linear Expansion | 17.3 | μm/m·K | 0-100°C | ASTM E228 |
| Electrical Resistivity | 720 | n|°¤m | 20°C | ASTM B193 |
| Magnetic Permeability | 1.02 | μ/μ₀ | Room Temp | ASTM A342 |
| Curie Temperature | None | - | - | Non-magnetic |
📏 Product Specifications
| Specification | Available Range | Standard Length | Custom Available | Tolerance |
|---|---|---|---|---|
| Diameter | 3mm - 300mm | Various | Yes | h9 tolerance |
| Length | 1m - 12m | 6m | Yes | +50mm/-0mm |
| Surface Finish | Hot Rolled, Cold Drawn, Peeled | Cold Drawn | Yes | Ra ≤ 1.6μm |
| Straightness | 1mm/m max | Standard | Precision | ASTM A276 |
| End Condition | Cut, Chamfered, Machined | Cut | Yes | Standard |
| Heat Treatment | Annealed, Stress Relieved | Annealed | Yes | ASTM A276 |
| Standards Compliance | ASTM A276, A582, A479 | A276 | Multiple | Full compliance |
| Machinability Rating | 78% (1212 = 100%) | Standard | - | Free machining |
| Test Certificate | Mill TC, EN 10204 3.1 | Mill TC | Yes | Standard |
| Packaging | Bundles, Hexagonal, Crates | Bundles | Custom | Export standard |
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Our Advantages in Processing บาร์กลมสแตนเลส 303
Superior Machinability Properties
The 303 stainless steel composition features optimized sulfur content that significantly improves machining characteristics, allowing for faster cutting speeds, better chip formation, and reduced tool wear during precision manufacturing operations.
Precise Round Bar Forming
Manufacturing process ensures consistent diameter tolerance and straightness throughout the length of the bar, making it ideal for high-precision turning operations and automated machining processes with minimal material waste.
Uniform Material Structure
Controlled manufacturing process delivers homogeneous grain structure and even distribution of alloying elements throughout the bar, resulting in consistent mechanical properties and predictable machining performance across batches.
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