Mechanical Properties
| Tensile strength (Rm) | Yield strength (Rp0.2) | Elongation (A5) | Reduction of Area (Z) | Hardness |
| ≥ 520 MPa | ≥ 205 MPa | ≥ 40% | ≥ 50% | ≤ 187 HBW; ≤90 HRBW; ≤300 HV |
Austenitic Stainless Steel Precision Ground Bars
303Cu Stainless Steel Round Bar AISI 303Cu | UNS S30331
303Cu stainless steel precision ground bar is suitable for customers who need efficient machining, stable dimensional accuracy, and a clean surface finish for high-volume production. As a free-machining austenitic stainless steel, 303Cu contains copper, sulfur, and selenium additions to improve machinability and support smoother cutting performance.
Compared with standard stainless steel grades, 303Cu offers better processing efficiency for parts that require easy cutting, good surface quality, and stable performance during machining. Its material characteristics help reduce tool wear, shorten processing time, and improve production consistency for turned and precision-machined components.
Compass Power Tech manufactures 303Cu stainless steel precision ground bars for automatic lathe parts, bolts, nuts, precision hardware, and other components where machinability and surface finish are important. For customers producing small precision parts in batches, 303Cu provides a practical balance between stainless steel corrosion resistance, processing efficiency, and finished part quality.
Chemical Composition (%)
| Grade | C | Si | Mn | P | S | Ni | Cr | Mo | Cu | Others |
| 303Cu | ≤ 0.15 | ≤ 1.00 | ≤ 3.00 | ≤ 0.20 | ≥ 0.15 | 8.00–10.00 | 17.00–19.00 | ≤ 0.60 | 1.50–3.50 | Se ≤ 0.30 |
Specifications
| Diameter | Tolerance | Roundness | Straightness | Standard Length | Surface Roughness |
| |
≤0.1mm/m | g6, h6, f7 | ≤1/2 | 2m 3m | Ra≤0.4 |
| |
≤0.1mm/m | g6, h6, f7 | ≤1/2 | 3m, 6m | Ra≤0.4 |
| |
≤0.1mm/m | g6, h6, f7 | ≤1/2 | 3m, 6m | Ra≤0.4 |
| |
≤0.05mm/m | g6, h6, f7 | ≤1/2 | 3m, 6m | Ra≤0.4 |
| |
≤0.05mm/m | g6, h6, f7 | ≤1/2 | 3m, 6m | Ra≤0.4 |
Additional Custom Services
- Cut-to-length service: Shaft length can be customized according to customer assembly requirements.
- End chamfering: Both ends of the shaft can be chamfered to simplify downstream machining and installation.
- Drawing-based machining: Shafts can be machined according to customer drawings and supplied as ready-to-assemble components.
- Surface rolling treatment: Surface rolling can be applied to improve surface hardness when higher wear resistance is required.
Packaging and Storage
To protect stainless steel precision ground shafting during sea freight and storage, Compass Power Tech uses anti-rust paper tube packaging. Before wrapping, anti-rust oil is applied evenly to the shaft surface, and anti-rust wax is applied inside the paper tube. This protection process helps reduce corrosion risk during transportation and ensures customers receive shafts in stable, ready-to-use condition.
Looking for Custom Metal Components for Your Application?
We manufacture precision ground shafts, stainless steel tubing, piston rods and aluminum alloy cylinder tubes for hydraulic, pneumatic, machinery, energy and transportation applications. Contact us for material selection, specifications and customization support.
