CNC Machining Stainless Steel Parts
The chromium element in stainless steel forms a dense passivation layer on its surface, effectively preventing substances like oxygen and water from coming into contact with the internal metal, making it highly resistant to rust and corrosion in various environments. Due to its excellent corrosion resistance, stainless steel ensures that structural components maintain the integrity of the engineering design over time. Stainless steel combines good strength and ductility, and it is easy to process and shape. It can be rolled, forged, welded, and cut into various shapes and sizes to meet the needs of different applications.
In CNC machining, stainless steel holds an important market position and is consistently favored by the machining industry due to its outstanding properties. Precision CNC machined stainless steel parts are commonly used in applications that require durability, stability, and a flawless surface finish, such as in medical engineering, mechanical equipment, automobiles, industrial equipment, automation devices, household appliances, toys, and more.
CNC Machining Materials for Stainless Steel Parts
Stainless steel is highly resistant to rust, making it suitable for applications where parts may be exposed to the environment for extended periods. Stainless steel also offers relatively good ductility and toughness. JUNYU offers a variety of stainless steel alloys, including food-safe grades.
The 300 series (such as 303, 304, etc.) are austenitic stainless steels (based on their crystal structure) and are the most widely produced grades worldwide. Austenitic stainless steels are known for their excellent corrosion resistance and high strength across a wide temperature range. With the exception of cold working, they are typically not heat treatable and are usually non-magnetic.
The 400 series stainless steels belong to the martensitic family and are less common than austenitic stainless steels. Martensitic steels are very hard and strong due to their higher carbon content, but they are more susceptible to rust in certain environments. They can be heat treated to significantly improve their hardness and are magnetic.
17-4 PH stainless steel is a high-strength, highly corrosion-resistant material, and after heat treatment, its mechanical properties are further enhanced, with pressure strength reaching 1100 – 1300 MPa. It is widely used in aerospace, energy, medical, chemical equipment, and industrial manufacturing fields, and is commonly used to manufacture shafts, turbine components, and other parts.
Nitronic 60 is an outstanding general-purpose material with excellent wear and corrosion resistance. After cold working, its yield strength is twice that of SS 304 and SS 316, or even higher, and it also offers excellent oxidation resistance. Common applications include bolts, valve stems, valve seats, pins, bushings, rings, bearings, and shafts.
About Stainless Steel Materials
Stainless-steel 303
SS303: Contains a lower proportion of chromium and nickel. The tensile strength and hardness increase after cold working. It is generally non-magnetic, but becomes magnetic after cold working.
| Tensile Strength，Yield (MPa) | Hardness | Density (p) | Maximum Temp | Elongation (ε) at break |
| 35,000 psi | Rockwell B95 | 0.29 Ibs / cu.in. | 2550°F | 42.5% |
Stainless steel 304L
The low carbon content of 304L stainless steel helps reduce or eliminate carbide precipitation during welding. This allows 304L stainless steel to be welded even in severely corrosive environments. Using 304L stainless steel eliminates the need to anneal the welded joints before final metal forming, saving time and effort.
| Tensile Strength，Yield (MPa) | Hardness | Density(p) | Maximum Temp | Elongation (ε) at break |
| 30,000 psi | Rockwell B80 (medium) | 0.29 lbs / cu. in. | 1500°F | 50% |
Stainless steel 316L
316L stainless steel, commonly referred to as A4 stainless steel in the fastener industry, is also known as marine-grade stainless steel. Due to the addition of molybdenum, it has excellent corrosion resistance, particularly its strong resistance to chloride ion corrosion. It can withstand the erosion of salts in marine environments such as seawater and sea breeze, making it ideal for various applications in marine areas, such as ship components, seawater treatment equipment, and marine construction equipment. As a result, it is often called marine stainless steel. It is the second most common austenitic stainless steel after 304/A2 stainless steel.
| Tensile Strength，Yield (MPa) | Hardness | Density(p) | Maximum Temp | Elongation (ε) at break |
| 30,000 psi | Rockwell B95 | 0.29 lbs / cu. in. | 1500°F | 39% |
Stainless steel 416
Alloy 416 stainless steel is a martensitic, free-machining chromium steel alloy that significantly improves machinability by adding elements such as sulfur and phosphorus. It is commonly regarded as the first free-machining stainless steel. Alloy 416 offers the highest machinability among all stainless steels, approximately 85% of that of free-cutting carbon steel. Martensitic stainless steels are heat treatable, and after heat treatment, they achieve excellent strength, hardness, and other properties. Although Alloy 416 and other martensitic stainless steels are not as corrosion-resistant as austenitic or ferritic stainless steels, they still exhibit good corrosion and oxidation resistance. Alloy 416HT is easy to machine, always magnetic, and has low friction properties that reduce wear and seizing.
| Tensile Strength，Yield (MPa) | Hardness | Density(p) | Maximum Temp | Elongation (ε) at break |
| 75,000 psi | Rockwell B80 | 0.28 Ibs / cu. in. | 1200°F | 22.5% |
Stainless steel 440C
440C stainless steel is a high carbon, high chromium martensitic stainless steel, known for its good mechanical properties, strong corrosion resistance, magnetism, and certain heat resistance. After heat treatment, 440C stainless steel can achieve high strength and hardness, with excellent wear resistance and fatigue resistance, making it suitable for components that require high mechanical performance. 440C stainless steel is commonly used in tool manufacturing, bearing manufacturing, medical devices, watch components, and more.
| Tensile Strength，Yield (MPa) | Hardness | Density(p) | Maximum Temp | Elongation (ε) at break |
| 110,000 psi | Rockwell C20 | 0.28 Ibs / cu.in. | 800°F | 8% |
Other Stainless Steel Materials
SS201: The surface is polished without bubbles or pinholes, and is commonly used in the production of high-quality materials such as watch cases and watchband bottom covers.
SS301: Contains a lower proportion of chromium and nickel, and its tensile strength and hardness increase during cold working. It is generally non-magnetic, but becomes magnetic after cold working.
SS304: It has good corrosion resistance, heat resistance, low-temperature strength, and mechanical properties. It also has good hot workability, such as stamping and bending, with no heat treatment hardening and is non-magnetic.
SS316: It has similar properties to 304 but offers higher corrosion and chemical resistance, making it particularly suitable for marine, chemical, and pharmaceutical industries.
China’s Best Stainless Steel Parts Machining Manufacturer – JUNYU
China’s Best Stainless Steel Parts CNC Machining Manufacturer – JUNYU.
If you are looking for a manufacturer that provides high-quality CNC machined parts, JUNYU is a great choice. With over 10 years of CNC machining experience, JUNYU has become one of the most professional and competitive manufacturers specializing in precision stainless steel parts machining, equipped with advanced CNC machines that meet the highest standards and premium quality.
Benefits of our stainless steel parts CNC machining services
- We offer competitive prices along with ISO9001 certification, material certifications, and surface treatment options such as anodizing, nickel plating, zinc plating, blackening, and chrome plating.
- With over 10 years of CNC machining experience, we provide reliable part design reviews, optimization suggestions, and technical support.
