+86-13928348837
China Stainless Steel CNC Machining - Top Suppliers & Reliable Factory for Precision Parts Manufacturing
We maintain a full inventory of austenitic, martensitic, precipitation-hardening, and specialty stainless steels to meet the most demanding mechanical performance and corrosion resistance requirements:
Austenitic Stainless Steels
303 Stainless Steel
A free-machining austenitic stainless steel with excellent machinability, ideal for high-volume automated parts, threaded components, and fittings requiring good corrosion resistance.
304 / 304L (18-8) Stainless Steel
The most versatile austenitic stainless steel, offering superior corrosion resistance, formability, and weldability. Widely used in food processing, chemical, medical device, and general machinery applications.
316 / 316L Stainless Steel
Molybdenum-enhanced austenitic stainless steel with significantly better resistance to chloride corrosion and pitting than 304 series. The preferred choice for marine environments, chemical equipment, high-end medical devices, and pharmaceutical industries.
Nitronic 60 (218 SS)
A high-performance nitrogen-strengthened austenitic stainless steel offering an exceptional combination of high wear resistance, strength, and corrosion resistance. Particularly suitable for critical applications involving galling and seizing resistance, such as bearings, valve seats, bushings, and food processing equipment.
Martensitic Stainless Steels
416 Stainless Steel
A free-machining martensitic stainless steel that achieves higher strength through heat treatment. Suitable for shafts, gears, and valve components requiring good machinability along with moderate strength and corrosion resistance.
410 & 420 Stainless Steel
General-purpose martensitic stainless steels. 410 offers moderate strength and corrosion resistance; 420, with higher carbon content, achieves greater hardness through heat treatment. Commonly used in cutlery, shafts, molds, and wear-resistant parts.
440C Stainless Steel
A high-carbon, high-chromium martensitic stainless steel with the highest hardness among stainless steels (can be hardened to HRC 58+). Exceptional wear resistance makes it ideal for high-end bearings, valve components, surgical instruments, and cutlery.
Precipitation-Hardening Stainless Steels
17-4 PH (630) Stainless Steel
The most widely used precipitation-hardening stainless steel. It achieves high strength (up to H1100 condition) through aging treatment while maintaining good corrosion resistance. Ideal for aerospace, marine, and high-stress structural applications.
15-5 PH Stainless Steel
An improved precipitation-hardening stainless steel with performance similar to 17-4 PH, but offering better transverse toughness and dimensional stability during heat treatment.
Frequently Asked Questions
Q
What is the difference between 304 and 316 stainless steel?
316 stainless steel contains molybdenum (typically 2–3%), which significantly enhances its resistance to chloride-induced corrosion and pitting compared to 304. While 304 is suitable for most general-purpose environments, 316 is preferred for marine, pharmaceutical, and chemical processing applications where exposure to harsh corrosives is expected.
Q
When should I choose precipitation-hardening stainless steel like 17-4 PH over austenitic grades?
Precipitation-hardening grades such as 17-4 PH and 15-5 PH are ideal when you need a combination of high strength, good corrosion resistance, and relatively easy machinability in the annealed condition. They are commonly selected for aerospace components, high-stress structural parts, and marine hardware where standard austenitic steels cannot provide sufficient mechanical strength.
Q
Which stainless steel grade offers the best machinability for high-volume CNC production?
303 and 416 stainless steels are specifically formulated as free-machining grades. 303 is an austenitic grade suited for parts requiring good corrosion resistance, while 416 is a martensitic grade that can be heat treated for higher strength. Both are excellent choices for high-volume automated CNC machining of threaded components, shafts, and fittings.
Q
What makes 440C stainless steel unique compared to other stainless grades?
440C is distinguished by its exceptionally high carbon and chromium content, allowing it to achieve the highest hardness of any stainless steel — up to HRC 58+. This makes it the top choice for applications demanding maximum wear resistance, such as precision bearings, valve balls and seats, surgical instruments, and high-quality cutlery blades.
Q
What is Nitronic 60 and what advantages does it offer over standard stainless steels?
Nitronic 60 (218 SS) is a nitrogen-strengthened austenitic stainless steel engineered to deliver superior resistance to galling and seizing — a common failure mode in metal-to-metal contact applications. Compared to standard austenitic grades, it offers higher strength, better wear resistance, and comparable corrosion resistance, making it ideal for bushings, valve seats, fasteners, and food processing equipment.
Q
How do I choose between 410 and 420 stainless steel for my application?
Both 410 and 420 are general-purpose martensitic stainless steels. 410 provides moderate hardness and corrosion resistance and is suitable for general structural and mechanical parts. 420, with its higher carbon content, can be heat treated to achieve significantly greater hardness, making it the preferred choice for cutting tools, molds, blades, and wear-resistant components where maximum surface hardness is critical.
Finishes and Post-Processing Options
The zinc alloy substrate is highly suitable for various surface treatments to enhance decoration, protection, or functionality:
Electroplating: Such as chrome, nickel, gold, or silver plating, providing a highly decorative appearance, excellent wear and corrosion resistance. This is the most common choice.
-
Passivation or Chromate Conversion Coating:
-
Powder Coating:
-
Painting:
-
Physical Vapor Deposition (PVD):
Design and Machining Considerations
-
Process Selection:
-
Design Considerations:
-
Material Selection:
Zamak 3 and 5 are suitable for the vast majority of general-purpose parts requiring good appearance and strength; ZA-8 is better for wear and bearing applications; for making rapid tooling, choose specialized alloys like Kirksite.
Ready to Start Your CNC Project?
Send us your drawings to receive professional manufacturing solutions.