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China Alloy Steel CNC Machining Factory: Quality Parts from Reliable Suppliers for All Industries
We maintain a complete inventory of high-quality alloy steels, including structural steel, carburizing steel, quenched & tempered steel, and tool steel, to meet the stringent requirements of diverse applications:
Low-Carbon Steel / Free-Machining Steel
1018 1018 Steel
A general-purpose low-carbon steel with excellent weldability and machinability. Suitable for surface carburizing/quenching to achieve a hard, wear-resistant surface with a tough core. Commonly used for shafts, pins, gears, etc.
1215 1215 Steel
A high-sulfur free-machining steel with superior chip-breaking performance, enabling high surface finish quality and faster machining speeds. Ideal for mass production of standard parts such as bolts, nuts, and bushings.
Chromium-Molybdenum Alloy Structural Steel (High-Strength)
4130 4130 Steel
A chromium-molybdenum alloy steel with excellent strength, toughness, and weldability. A classic material for aerospace structural tubing (e.g., aircraft engine mounts) and high-performance racing chassis, typically normalized or quenched & tempered.
4140 4140 Steel
One of the most widely used chromium-molybdenum alloy steels, offering high strength, good wear resistance, and impact toughness. Achieves different strength levels through quenching & tempering. Widely used for gears, shafts, couplings, and die sets.
4140 PH 4140 PH Steel (Pre-Hardened)
Supplied in a pre-quenched & tempered condition (typically HRC 28–32), offering stable mechanical properties and machinability. Can be machined directly without post-heat treatment, avoiding deformation risks. Commonly used for dies and mechanical components.
4340 4340 Steel
A high-strength nickel-chromium-molybdenum alloy steel with exceptional strength, toughness, and fatigue resistance, especially suitable for large-section critical load-bearing components. The preferred material for aircraft landing gear, heavy-duty drive shafts, and high-performance racing crankshafts.
Tool Steel (High Wear Resistance / High Hardness)
A2 A2 Tool Steel
An air-hardening cold-work tool steel with good wear resistance, moderate toughness, and minimal heat treatment deformation. Widely used for precision stamping dies, shear blades, and gauges.
O1 O1 Tool Steel
An oil-hardening general-purpose tool steel renowned for excellent edge retention, machinability, and simple heat treatment. Commonly used for hand tools, gauges, cutting tools, and low-life molds.
Frequently Asked Questions
Q What is the difference between 4140 and 4140 PH steel?
4140 steel is typically supplied in an annealed or normalized state and requires heat treatment after machining to achieve the desired hardness. 4140 PH (Pre-Hardened) is delivered already quenched and tempered to approximately HRC 28–32, allowing it to be machined directly without further heat treatment — significantly reducing the risk of dimensional distortion.
Q Which alloy steel is best suited for aerospace applications?
4130 and 4340 steels are the most commonly specified alloy steels for aerospace use. 4130 is widely used for structural tubing and engine mounts due to its excellent weldability and strength-to-weight ratio. 4340 is preferred for highly stressed components such as landing gear and drive shafts, thanks to its superior strength, toughness, and fatigue resistance.
Q What makes 1215 steel ideal for high-volume machining?
1215 is a free-machining steel with a high sulfur content that promotes excellent chip-breaking during cutting. This results in faster machining speeds, improved surface finish, and reduced tool wear — making it highly cost-effective for mass production of small precision parts such as bolts, nuts, and bushings.
Q What is the key advantage of A2 tool steel over O1 tool steel?
A2 tool steel is air-hardening, which means it experiences significantly less distortion during heat treatment compared to O1, which requires oil quenching. This makes A2 the preferred choice for precision dies and gauges where dimensional stability is critical. O1, on the other hand, offers superior machinability and edge retention, making it ideal for cutting tools and hand tools.
Q Can 1018 steel be used for structural load-bearing parts?
1018 steel is suitable for light to moderate load-bearing applications such as shafts, pins, and gears, particularly when surface carburizing is applied to improve hardness and wear resistance. However, for heavy-duty or high-stress structural components, higher-strength alloy steels such as 4140 or 4340 are recommended.
Q How do I choose the right alloy steel for my application?
Selecting the right alloy steel depends on several factors: required mechanical properties (strength, hardness, toughness), machinability requirements, heat treatment capabilities, and the operating environment. For general machining, 1018 or 1215 are cost-effective options. For high-strength structural parts, 4140 or 4340 are preferred. For tooling and dies, A2 or O1 tool steels offer the wear resistance and precision needed. Our engineering team is available to help you identify the optimal material for your specific application.
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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