Carbon Steel Hydraulic Tubing

-- Steady & Reliable Manufacturer --

Carbon steel hydraulic tubing serves as the essential, high-pressure fluid conduit system within the fluid power industry, acting as the rigid arterial network that conveys high-velocity hydraulic oil safely between pumps, control valves, accumulators, and linear actuators. At Jiangsu Hengcai Hydraulic Mechanical Co., Ltd., we manufacture high-performance cold-drawn seamless carbon steel tubes specifically engineered to handle intense continuous duty cycles, high operating pressures, and demanding structural stresses. Our precision tubing lines are widely utilized across complex industrial environments, including automated factory production lines, automotive manufacturing assembly systems, heavy agricultural implements, plastic injection molding machinery, and construction equipment chassis. Managing high fluid velocities and intense pressure spikes requires a tube with exceptional structural integrity; any internal material defects, surface seams, or dimensional variations can lead to structural bursts, dangerous hot-oil leaks, and catastrophic system pressure losses. To eliminate these operational risks, our production process utilizes premium, fully killed carbon steel billets that are cold-drawn over a mandrel to achieve narrow dimensional tolerances and absolute wall thickness uniformity. Following the drawing process, the tubes undergo specialized bright annealing heat treatments in a controlled atmosphere furnace, which relieves internal material stresses while maintaining a scale-free, pristine internal and external surface finish. This clean, smooth inner profile is critical for minimizing fluid friction losses, preventing turbulent oil flow, and ensuring that no loose mill scale or oxidized particles enter the circuit to clog sensitive proportional valves. By combining tight geometric tolerances with rigorous eddy-current and hydrostatic testing, our seamless carbon steel hydraulic tubing delivers the reliable containment and long-term durability needed to keep your high-pressure fluid networks running efficiently.

Key Features

Engineering Excellence at a Glance

Feature	Technical Advantage
Cold-Drawn Seamless Structure	Eliminates longitudinal weld lines, providing completely uniform strength and high pressure containment profiles.
Controlled Bright Annealing	Relieves internal stresses and restores material ductility, allowing easy, crack-free tube bending and flaring.
Scale-Free Pristine Bore	Prevents oxidized particles from breaking loose and contaminating sensitive internal hydraulic valves.
Strict Wall Thickness Uniformity	Ensures predictable bursting thresholds and high burst safety factors under extreme system pressure spikes.
Excellent Material Ductility	Supports automated cold bending, manual offsetting, and 37-degree flaring operations on the shop floor.
Oiled Anti-Rust Exterior Film	Provides temporary corrosion defense during factory transit and warehouse storage phases.
High-Accuracy Dimensional Outside Tolerances	Guarantees a tight, leak-free connection when using standard compression fittings and bite-type sleeves.

Specifications Guide

Hydraulic Cylinder Specifications Guide

International Material Standards: Manufactured and certified to comply fully with global specifications including EN 10305-1, EN 10305-4, DIN 2391, and ASTM A179.
Base Steel Chemical Chemistry: Utilizing high-grade low-carbon steel formulations such as St37.4, St52.4, E235, and E355 configurations.
Outside Diameter Sizing Matrix: Available in an extensive high-precision manufacturing range from 4mm up to 80mm outside diameters.
Wall Thickness Dimensional Scope: Produced with wall thickness dimensions ranging from 0.5mm up to heavy-walled 10mm options.
Delivery Structural Heat Condition: Supplied primarily in the NBK (Bright Annealed) condition to maximize material flexibility and bending.
Hydrostatic Pressure Validation Threshold: Every production lot is internally pressurized up to standard testing limits ranging from 20MPa to 50MPa.
Internal Surface Roughness Metric: Finished internally to maintain an ultra-smooth profile reading below a strict Ra 0.25 microns threshold.

Selection Guide

How to Select a Hydraulic Cylinder

Calculate Peak Working and Burst Pressures: Apply Barlow’s formula to determine the necessary wall thickness and steel grade to maintain a minimum 4:1 safety factor.
Verify Cold Bending Radii Requirements: Select bright annealed (NBK) tubes to ensure the steel can bend smoothly without collapsing or cracking.
Match Tube Dimensions with Fitting Standards: Check that outside diameter metrics line up with your metric DIN 2353 bite-type or imperial JIC 37° flared fittings.
Assess Internal Flow Velocity Targets: Size the internal diameter carefully to keep oil speeds under 5 m/s in pressure lines, preventing heat buildup.
Confirm Cleanliness Level Specifications: Specify phosphate-treated or bright annealed options if the tubing feeds high-precision servo or proportional valves.
Select the Optimal Carbon Steel Grade: Choose high-strength E355 or St52.4 steel to minimize wall thickness and total weight while maintaining pressure ratings.
Evaluate Environmental Rust Risks: Opt for zinc-plated or passivated external finishes if tubes are exposed to humid outdoor conditions.

Why Choose Us

Why Choose HydraForce

Precision Cold-Drawing Infrastructure: Our factory utilizes advanced hydraulic drawing benches that ensure excellent wall thickness concentricity and tight diameter control.
Controlled Atmosphere Bright Annealing: Our oxygen-free heat treatment line prevents oxidation scale, ensuring an exceptionally clean internal bore.
100% Non-Destructive Eddy-Current Scanning: Every single millimeter of our hydraulic tubing undergoes online eddy-current testing to detect hidden sub-surface flaws.
Comprehensive Hydrostatic Validation Testing: We pressure-test our hydraulic tubing lines to guarantee structural integrity and leak-free performance under load.
Strict Internal Bore End-Capping Protocols: After cleaning and oiling, tube ends are plugged with plastic caps to keep out dust during shipping and storage.
Full Metallurgical Laboratory Documentation: We issue comprehensive EN 10204 3.1 certificates detailing chemical composition and mechanical values for every batch.

FAQ

Frequently Asked Questions

Q: What is the difference between welded and seamless steel tubing for high-pressure hydraulic circuits?
A: Welded tubing has a longitudinal seam that can act as a point of weakness under pressure spikes. Seamless tubing is drawn from a solid billet, giving it completely uniform structural strength and a higher safety factor under extreme pressures.

Q: Why is the NBK (Bright Annealed) heat-treatment condition preferred for plumbing hydraulic systems?
A: Bright annealing heats the steel in an oxygen-free gas environment. This prevents rough iron oxide scale from forming inside the tube while softening the metal, making it easy to bend, flare, and form without cracking.

Q: How do I store carbon steel hydraulic tubes to prevent rust before installation on my equipment?
A: Tubes should be kept indoors in a dry, climate-controlled warehouse. Our tubes are shipped with an external anti-rust oil film and plastic end caps, which should remain in place until final assembly.

Jiangsu Hengcai Hydraulic Mechanical Co., Ltd.

Established in 1988, Jiangsu Hengcai Hydraulic Machinery Manufacturing Co., Ltd. has been dedicated to the research and development as well as the manufacturing of hydraulic cylinders. Situated in Jianhu County, Yancheng City, Jiangsu Province, the factory enjoys a strategic location with Dafeng Port to the east, Xuzhou to the west, Nantong to the south, and Lianyungang to the north. The Xinchang Railway traverses the area, and the 204 National Highway, Coastal Expressway, Yancheng-Xuzhou Expressway, and Ningjingyan Expressway crisscross the region, providing a well-connected transportation network. The proximity to Yancheng Nanyang International Airport, just a 70-kilometer drive away, has laid a solid foundation for the company's rapid growth.

As China Carbon Steel Hydraulic Tubing Suppliers, our hydraulic cylinder products are widely used across various industries, including petroleum, chemical, marine, coal, metallurgy, engineering, construction, machine tools, agricultural machinery, and transportation, serving over 40 large and medium-sized main machine factories. Our products are also exported to the United States, Japan, Russia, and other countries and regions, accompanying the main machines, thus expanding our product's reach globally.

Adhering to the corporate spirit of "Advocate the persistence, endeavour for the winning," and the corporate philosophy of "Technological innovation and technology, people-oriented," we strive to provide reliable products and services in return for the trust of our valued customers.