+86-13928348837
Alloy Steel CNC Machining Services from China Suppliers | Precision Parts from a Leading Factory
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
S
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.
S
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)
A
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.
A
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.
A
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.
A
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)
T
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.
T
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 Steel and 4140 PH Steel?
4140 Steel is typically supplied in an annealed or normalized condition and requires heat treatment (quenching & tempering) after machining to reach the desired hardness. 4140 PH (Pre-Hardened) Steel is already delivered in a quenched & tempered state (HRC 28–32), allowing direct machining without further heat treatment — reducing lead time and minimizing the risk of dimensional distortion.
Q
Which alloy steel is best suited for aerospace and high-performance automotive applications?
4340 Steel is widely regarded as the top choice for these demanding applications. Its nickel-chromium-molybdenum composition delivers exceptional tensile strength, toughness, and fatigue resistance — making it ideal for aircraft landing gear, heavy-duty drive shafts, and racing crankshafts. 4130 Steel is also commonly used for aerospace structural tubing and racing chassis due to its excellent weldability and strength-to-weight ratio.
Q
What is the advantage of using 1215 Free-Machining Steel over standard low-carbon steel?
1215 Steel contains elevated sulfur content, which promotes the formation of manganese sulfide inclusions that act as chip-breakers during machining. This results in superior surface finish, reduced tool wear, and significantly faster machining speeds compared to standard low-carbon steels like 1018. It is especially advantageous for high-volume production of precision fasteners, bushings, and fittings.
Q
How do A2 and O1 Tool Steels differ, and how do I choose between them?
The primary difference lies in their hardening method and resulting properties. A2 Tool Steel is air-hardened, which means it undergoes minimal distortion during heat treatment — making it ideal for precision dies and gauges where dimensional stability is critical. O1 Tool Steel is oil-hardened and is prized for its excellent machinability and edge retention, making it a practical choice for cutting tools, hand tools, and general-purpose molds where tight tolerances are less critical.
Q
Can 1018 Steel be surface hardened, and what process is typically used?
Yes. 1018 Steel is well-suited for case hardening (surface carburizing followed by quenching). This process enriches the outer layer with carbon, creating a hard, wear-resistant surface while maintaining a tough, ductile core. It is a cost-effective solution for components such as shafts, pins, and gears that require both surface hardness and core toughness.
Q
What types of alloy steels do you stock, and can you supply custom sizes?
We maintain a comprehensive inventory of alloy steels including low-carbon steels (1018, 1215), chromium-molybdenum structural steels (4130, 4140, 4140 PH, 4340), and tool steels (A2, O1). Standard stock forms include round bars, flat bars, and plates in a range of sizes. Custom cutting and value-added processing services are also available to meet specific project requirements — please contact us for a tailored quote.
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.