Products Description
Our Advantages
1. Pressure Resistance
- Our pipes are manufactured using a cold-drawing process, ensuring uniform wall thickness and consistent high-pressure resistance. The pipes undergo hydrostatic testing to ensure no leakage or deformation under high pressure.
- The optimized heat treatment process enhances the pipe's toughness and strength, enabling it to withstand repeated impacts under high pressure and reducing the risk of cracking.
2. Dimensional Accuracy
- The 4140 steel tube is cold-drawn multiple times using a CNC machine, ensuring strict control over dimensional tolerances. Outer diameter tolerance is controlled within ±0.05mm, and wall thickness tolerance within ±0.1mm, reducing secondary processing costs.
- Before packaging, the pipes undergo 100% dimensional inspection using high-precision calipers, thickness gauges, and straightness testing equipment to ensure compliance with ASTM A519 standards or customer requirements.
3. Surface Quality
- Our cold-drawing process yields a smooth surface with a surface roughness of Ra ≤ 1.6 μm. For pipes used in hydraulic cylinders, we support honing, tumbling, and precision drilling.
- Our pipes undergo rigorous surface quality testing to ensure they are free of scratches, scale, cracks, and other defects.
4. Machining and Welding Performance
- 4140 steel tube is supplied in an annealed state, allowing for direct turning, drilling, and boring. We maintain strict control over the dimensions and surface quality of our pipes, minimizing secondary processing steps for our customers.
- Our pipes undergo a stress-relief process after cold drawing to prevent cracks caused by stress concentration during welding.
5. Customization Capabilities
- We offer flexible customization solutions to meet the needs of various applications. Custom sizes, surface finishes, and heat treatments are supported.
- We also provide one-stop post-processing services such as rough machining, honing, chamfering, threading, boring, and tapping, reducing secondary processing costs for our customers.
application areas
- Hydraulic system components: hydraulic cylinders, piston rods, hydraulic struts, hydraulic hoses.
- Transmission system components: drive shafts, half shafts, connecting rods, rocker arms, pin sleeves.
- Working device components: internal reinforcing tubes for excavator booms/sticks, articulated sleeves for loader buckets, etc.
- Oil and gas: drilling tools, joints, and mechanical parts.
- Construction and mining machinery: structural and load-bearing components such as rollers, axles, and heavy machinery parts.
Chemical Composition
| Element | Cr (%) | P (%) | Mo (%) | S (%) | Mn (%) | Si (%) | C (%) |
| 4140 | 0.80–1.10 | ≤0.035 | 0.15–0.25 | ≤0.040 | 0.75–1.00 | 0.15–0.35 | 0.38–0.43 |
Mechanical Properties
| Property | Tensile Strength | Yield Strength | Elongation | Reduction of Area | Hardness |
| Value | 850 – 1000 MPa | ≥ 655 MPa | ≥ 12 % | ≥ 45 % | 28 – 32 HRC |
Possible Alternative Grades
| Alternative Grades | Reasons |
| 4130 | With a lower carbon content than 4140 steel, it offers better weldability but slightly lower strength. Suitable for structural components and medium-load mechanical parts. |
| 42CrMo4 (EN 1.7225) | Similar products in Europe are widely used in mechanical engineering. Mechanical properties are similar, with slight differences in composition. |
| SCM440 | An equivalent to the Japanese standard 4140, commonly used in the automotive and machinery industries. |
Products Show
Testing Equipment
Factory Equipment
Pickling equipment
Products Package
FAQ
Q: What condition is your 4140 tubing in?
A: Our tubing is supplied in annealed condition, but we also offer Normalized condition, Q&T, and other conditions.
Q: What are the machinability properties of the tubing?
A: Our tubing is delivered in annealed condition by default (hardness ≤197HB), and can be directly machined by turning, drilling, boring, and other machining operations.
Q: Can the tubing undergo custom surface treatments?
A: Custom surface treatments include blackening, phosphating, galvanizing, and rust-proofing spraying; for hydraulic applications, we offer honing and tumbling polishing.
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