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Stainless Steel CNC Machining Factory in China - Top Suppliers 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:
Specialized Stainless Steel Material Library
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 Popular
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.
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.
17-4 PH (630) Stainless Steel Aerospace
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.
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 Hardest
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.
Nitronic 60 (218 SS) High Performance
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.
Frequently Asked Questions
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What is the difference between 304 and 316 stainless steel?
Both are austenitic stainless steels, but 316/316L contains added molybdenum (2–3%), which significantly improves its resistance to chloride corrosion and pitting. 316 is preferred in marine, pharmaceutical, and chemical environments, while 304 is more cost-effective for general-purpose applications.
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When should I choose a precipitation-hardening stainless steel like 17-4 PH or 15-5 PH?
Precipitation-hardening grades such as 17-4 PH and 15-5 PH are ideal when you need both high mechanical strength and good corrosion resistance — typical in aerospace, defense, and high-stress structural components. They can be aged to various strength conditions (H900 to H1150) to meet specific design requirements.
Q
Which stainless steel grade offers the best machinability?
303 and 416 stainless steels are specifically designed for free-machining. They contain added sulfur which improves chip-breaking and reduces tool wear, making them the top choices for high-volume CNC turning, threading, and automated production of precision parts.
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What makes 440C stainless steel unique compared to other stainless grades?
440C has the highest carbon content among stainless steels, allowing it to be heat-treated to a hardness of HRC 58 or higher — the hardest achievable in any stainless steel. This makes it exceptionally wear-resistant, ideal for precision bearings, cutting tools, surgical instruments, and high-end valve components.
Q
What is Nitronic 60 and why is it used in galling-prone applications?
Nitronic 60 (218 SS) is a nitrogen-strengthened austenitic stainless steel engineered to resist galling and seizing — two common failure modes in metal-on-metal contact. Its unique composition provides superior wear resistance and anti-galling properties even without lubrication, making it the material of choice for valve seats, bushings, and food processing equipment.
Q
How do I choose between 410 and 420 stainless steel?
Both are martensitic stainless steels, but 420 contains higher carbon content, enabling it to achieve greater hardness through heat treatment. Choose 410 when moderate strength and corrosion resistance are sufficient (e.g., general hardware, shafts). Opt for 420 when higher hardness and wear resistance are required, such as in cutlery blades, molds, and wear-resistant components.
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.
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Passivation or Chromate Conversion Coating:
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Powder Coating:
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Painting:
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Physical Vapor Deposition (PVD):
Design and Machining Considerations
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Process Selection:
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Design Considerations:
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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.
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