The versatility of stainless steel is undisputed. It is used in various CNC (Computer Numerical Control) machining industries. Many stainless steel items are produced using versatile manufacturing methods in CNC machining. These methods benefit from the precision of computer-controlled milling machines, drills, lathes, and other cutting tools that can produce accurate, repeatable parts efficiently and cost-effectively.
The presence of chromium in alloys is why stainless steel is better than regular steel. The chemical composition of all stainless steel contains about 10.5% chromium. The existence of chromium in the steel makes it resistant to corrosion. The variation between different types of steel depends on the presence of varying alloying elements that further improve corrosion resistance, heat treatment, and machinability. Please remember that heat treatment can significantly change the metal’s mechanical properties.
Why CNC Machining in Stainless Steel?
The use of stainless steel in CNC machining offers countless advantages, including:
- Strength. CNC machining of stainless steel provides exceptional strength to the parts being machined and is known for its strength-to-weight ratio. Because of this ability, parts made from thinner materials can be machined. Stainless steel can resist extreme temperatures. Therefore, we can further improve its strength through cold and hot hardening so that it can fulfill its intended use. Among the many types of metallurgical structures of stainless steel, martensitic stainless steels have the highest strengths.
- Extremely versatile and flexible. Stainless steels are very flexible and can be readily shaped, welded, machined, and cut, just like conventional steels. The addition of sulfur can also further increase formability. To date, austenitic stainless steel has been considered the most malleable and versatile, while the other metallurgical structures are somewhat brittle. The formability of stainless steel combined with today’s innovative manufacturing techniques is a great combination that can be used in various applications.
- Corrosion resistance. Stainless steel can be used in many different environments because it has a high resistance to corrosion. Low alloy steel grades can only withstand atmospheric conditions. However, high alloy steel grades are resistant to acids, alkalis, and chloride solutions. Austenitic stainless steel contains a higher chromium content, providing excellent resistance to highly corrosive environments.
- Low maintenance and durable. Because stainless steel can survive harsh environments and high temperatures and is low-maintenance, it is preferred for industrial machining applications. Because of these properties, stainless steel has a longer life cycle and is more cost-effective than other metals.
- Aesthetic appearance. Stainless steel is available in numerous finishes that offer a modern and attractive appearance that complements any space, whether it’s your kitchen, home, or other themes.
Stainless Steel Types for CNC Machining
Simiar to stainless steel casting, many stainless steel alloys are available for CNC machining.
SS 302: This is the austenitic variety of stainless steel and is known for its corrosion resistance and flexibility. The steel can be cold hardened but is easily converted to slow speed.
SS 303: This austenitic steel is readily machinable. 303 stainless steel has excellent toughness. However, its resistance and corrosion can sometimes resist because of the sulfur addition.
SS 304: This type of steel contains 8% nickel, 18% chromium, and a carbon concentration of 0.07% (usually maximum). 304 stainless steel has excellent corrosion resistance and formability after CNC machining, so it is widely used to manufacture various commercial and household appliances. Different resistance and fusion welding methods can easily weld this steel.
SS 316: This type is commonly used in harsh environments. Although 316 and 304 are the same, the only difference between them is the presence of an increased amount of molybdenum. The molybdenum gives 316 excellent heat and corrosion resistance. However, its machining is more complicated than others of all the common stainless steel.
SS 17-4 PH: This is a type of martensitic stainless steel that is hardenable by precipitation. These steels have a combination of mechanical properties, such as resistance, corrosion resistance, oxidation resistance, etc. However, the mechanical properties can be further improved by heat treatment.
SS 400 series: These steels contain 11 percent chromium and 1 percent manganese. To harden them, they are heat treated. The martensitic crystal form of these stainless steels is due to their high carbon content. Because of this structure, they exhibit high wear resistance and structural integrity after CNC machining. However, they do not exhibit excellent corrosion or rust resistance.
Stainless Steel CNC Machinining Service in CFS
CFS Machining shop is proud to help you take your stainless steel part or assembly from print to production without a hitch. We have been in this industry for more than 30 years and have vast experience in stainless steel precision CNC machining. We also work as one of the leading Chinese CNC machining specialists.
With our CNC machining services, we create your custom stainless steel parts for various applications in energy, medical, agriculture, industrial automation, marine, robotics, and construction industries. CFS will machine your CNC parts directly from the information in a CAD file and engineering drawing uploaded to our platform. We ensure that the parts we produce meet your requirements and the dimensions perfectly match your design.
Our CNC machining capabilities for stainless steel components include:
- Part Weight Range: 0.01kg-50kgs
- Tightest tolerance: ±0.01 mm
- Smooth machined surface, can reach Ra 0.4
- Raw Material: Stainless steel billets, stainless steel castings, stainless steel forgings, etc.
- Surface Finish Methods: Electropolishing, powder coating, mirror & brushed polishing, etc
Tips on Stainless Steel CNC Machining
Stainless steel is relatively harder than other materials like aluminum, mild steel, alloy steel, copper, etc., so machining stainless steel parts will be challenging.
However, CFS machining shop produces a high quantity of stainless steel machined parts. We have prepared the following guideline based on our experience and practice in producing stainless steel parts with the CNC machining process:
- Choose the right alloy: Try to design your machined stainless steel parts with a common stainless steel alloy in China. It is suggested to select a proper stainless steel alloy according to the working environment.
- Heat treatment before machining. The heat treatment helps reduce the stainless steel hardness to be more accessible for machining.
- Excellent lubrication. The use of a cooling, lubricating fluid can reduce maximum heat and lubricate the product surface simultaneously. We usually use a mixed lubricant of nitrogen tetrafluoride and engine oil. We can ensure that this lubricant is very suitable for machining stainless steel parts with smooth surfaces based on our practice.
- During the tool changing time, the use of high-quality cutting tools will help obtain smooth part surfaces and small tolerances.
- Lower cutting speed. Selecting a lower cutting speed can reduce heat generation and facilitate chip breaking.
If you are looking for a reliable and quality CNC machining shop in China offering reasonable prices, feel free to reach us and get a free quote.