50mm ASTM A519 Hydraulic Cylinder Pipe Alloy Steel Mechanical Tubing
ASTM A519 hydraulic cylinder tubing is seamless carbon or alloy steel mechanical tubing intended for precision-machined components such as hydraulic cylinder barrels. For a 50 mm tube size, the tubing can be supplied cold drawn and subsequently honed or skived and roller burnished to achieve a controlled bore dimension and low internal surface roughness.
ASTM A519 covers seamless hot-finished and cold-finished mechanical tubing manufactured in carbon and alloy steel grades. The standard applies to round tubing up to 325 mm outside diameter, making the 50 mm size well within its dimensional scope.
Common material options for hydraulic cylinder tubing include 1010, 1020, 1026, 4130 and 4140, selected according to required strength, machinability, welding requirements and heat-treatment condition.
Specifications
| Item |
Specification |
| Product |
Seamless Mechanical Steel Tube for Hydraulic Cylinder |
| Standard |
ASTM A519 / ASTM A519M |
| Material |
Carbon Steel / Chromium-Molybdenum Alloy Steel |
| Typical Grades |
1010, 1020, 1026, 4130, 4140 |
| Nominal Size |
50 mm available |
| Outside Diameter |
30-325 mm |
| Wall Thickness |
3-35 mm, customizable |
| Length |
1-12 m, cut lengths available |
| Manufacturing Process |
Seamless, Cold Drawn |
| Bore Finishing |
Honing or Skiving and Roller Burnishing |
| Delivery Condition |
Cold Finished, Stress Relieved, Annealed, Normalized or Heat Treated as specified |
| ID Tolerance After Finishing |
H8 / H9 commonly available |
| Straightness |
Typically 0.2-0.5 mm/m depending on finished condition |
| Honed Bore Roughness |
Typically Ra 0.4-0.8 μm |
| Skived and Roller Burnished Bore Roughness |
Typically Ra 0.2-0.4 μm |
| Surface Condition |
Cold Drawn, Oiled, Honed ID or SRB ID |
| Inspection |
Dimensional Inspection, Chemical Analysis, Mechanical Testing, Surface Inspection |
ASTM A519 itself defines seamless mechanical tubing requirements and dimensional tolerances according to tube condition. Final hydraulic-cylinder bore tolerances and surface roughness should be specified separately on the purchase order because H8/H9 and honed or SRB surface requirements are finishing specifications rather than automatic ASTM A519 requirements.
Main Features
Precision Seamless Construction
ASTM A519 tubing is manufactured without a welded seam. Cold finishing can be used after hot working to obtain the required tube dimensions and mechanical characteristics. This construction is suitable for machining hydraulic cylinder barrels where circumferential dimensional consistency is important.
Controlled Hydraulic Cylinder Bore
After cold drawing, the internal diameter can be honed or processed by skiving and roller burnishing. Typical hydraulic-cylinder finished bore tolerances are H8 or H9. For a finished cylinder barrel, the required bore dimension should be specified by ID and tolerance rather than relying only on OD and wall thickness.
Low Internal Surface Roughness
Honed tubing commonly reaches approximately Ra 0.4-0.8 μm, while skived and roller burnished tubing can typically reach approximately Ra 0.2-0.4 μm. The smoother SRB surface is particularly useful where piston seals run directly against the tube bore.
Wide Material Selection
Low-carbon grades such as 1010, 1020 and 1026 provide good machinability and fabrication characteristics, while chromium-molybdenum grades such as 4130 and 4140 are available where higher strength or heat-treated performance is required.
Custom Cut Lengths
Tubing can be supplied in mill lengths or definite cut lengths according to drawings. ASTM A519 recognizes definite cut lengths when specified by the purchaser.
Our Advantages
Bore Tolerance Specified Separately from ASTM A519
One common purchasing problem is assuming that ordering "ASTM A519 tube" automatically defines the finished hydraulic-cylinder bore. It does not. ASTM A519 primarily controls the mechanical tubing itself, while the hydraulic bore usually requires an additional ID tolerance such as H8 or H9. We manufacture according to the complete drawing requirement, including nominal ID, finished ID tolerance, machining allowance and bore-finishing process. This reduces the risk of receiving ASTM-compliant tubing that still requires excessive internal machining.
Honing and SRB Selected According to Final Cylinder Requirements
Hydraulic cylinder manufacturers commonly need to choose between honing and skiving plus roller burnishing. Honing generally produces an approximately Ra 0.4-0.8 μm surface, while SRB can reduce roughness to approximately Ra 0.2-0.4 μm and is efficient for production quantities. The finishing method can therefore be specified according to required surface roughness, dimensional tolerance, cylinder design and subsequent machining rather than applying the same process to every tube.
Material and Heat-Treatment Condition Controlled Together
Mechanical properties of 1010, 1020, 1026, 4130 and 4140 can vary significantly with cold working, stress relieving, annealing, normalizing or quench-and-temper treatment. Material grade alone is therefore insufficient for a critical cylinder barrel. Orders can define both steel grade and final delivery condition, allowing chemical composition, dimensions, heat treatment and required mechanical properties to be checked as one manufacturing specification.
Execution Standards
| Standard |
Description |
| ASTM A519 / A519M |
Seamless Carbon and Alloy Steel Mechanical Tubing |
| EN 10305-1 |
Seamless Cold Drawn Tubes for Precision Applications |
| DIN 2391 |
Cold Drawn Precision Seamless Steel Tubes, commonly referenced for hydraulic applications |
| JIS G3445 |
Carbon Steel Tubes for Machine Structural Purposes |
| GB/T 3639 |
Cold Drawn or Cold Rolled Precision Seamless Steel Tubes |
| GB/T 8162 |
Seamless Steel Tubes for Structural Purposes |
Application
Hydraulic Excavator Boom Cylinder Barrel
A specific application is the barrel of a hydraulic excavator boom cylinder. Cold-drawn ASTM A519 tubing is machined and the internal bore is honed or skived and roller burnished to provide the dimensional accuracy and surface finish required for movement of the piston and sealing system. The tube can then undergo external machining, port connection fabrication and cylinder assembly according to the hydraulic cylinder design.
Chemical Composition
| Grade |
C % |
Mn % |
P % Max. |
S % Max. |
Si % |
Cr % |
Mo % |
| 1010 |
0.08-0.13 |
0.30-0.60 |
0.040 |
0.050 |
- |
- |
- |
| 1020 |
0.18-0.23 |
0.30-0.60 |
0.040 |
0.050 |
- |
- |
- |
| 1026 |
0.22-0.28 |
0.60-0.90 |
0.040 |
0.050 |
- |
- |
- |
| 4130 |
0.28-0.33 |
0.40-0.60 |
0.040 |
0.040 |
0.15-0.35 |
0.80-1.10 |
0.15-0.25 |
| 4140 |
0.38-0.43 |
0.75-1.00 |
0.040 |
0.040 |
0.15-0.35 |
0.80-1.10 |
0.15-0.25 |
Mechanical Properties
| Grade |
Typical Delivery Condition |
Tensile Strength |
Yield Strength |
Elongation |
Selection Consideration |
| 1010 |
Cold Finished / Stress Relieved |
To be specified by condition and drawing |
To be specified by condition and drawing |
To be specified |
Low-carbon grade with good forming and machining characteristics |
| 1020 |
Cold Finished / Stress Relieved |
To be specified by condition and drawing |
To be specified by condition and drawing |
To be specified |
Common carbon steel option for general cylinder barrels |
| 1026 |
Cold Finished / Stress Relieved |
To be specified by condition and drawing |
To be specified by condition and drawing |
To be specified |
Higher carbon and manganese content than 1020 |
| 4130 |
Annealed / Normalized / Heat Treated |
Depends on selected heat treatment |
Depends on selected heat treatment |
Depends on selected heat treatment |
Cr-Mo alloy steel for higher-strength components |
| 4140 |
Annealed / Normalized / Quenched and Tempered |
Depends on selected heat treatment |
Depends on selected heat treatment |
Depends on selected heat treatment |
Cr-Mo alloy steel for higher-strength and heat-treated applications |
Frequently Asked Questions
Q: Are you trading company or manufacturer?
A: Manufacturer, also can do trading.
Q: How long is your delivery time?
A: Generally speaking, it is 10-15 days if the goods are in stock, or it is 30-40 days if the goods are not in stock, according to quantity.
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A: Yes, we could offer the sample for free charge but need pay the cost of freight.
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A: Payment ≤ 2000 USD, 100% in advance. Payment ≥ 2000 USD, 30% T/T in advance, balance before shipment. If you have another question, please feel free to contact with me.