About Us
Eastern Steel Manufacturing Co.,Ltd is a leading manufacturer and distributor of seamless steel pipe, welded steel pipe, OCTG products and fittings. We supply first-step processing, semi-finished parts and finished parts to help our clients meet fabrication requirements beyond their capacity or to improve operations by moving forward the pre-production processing.
News
In this column you can find the steel pipe related articles you need, including industry trends, product standards and materials, and some technical guidelines.
Services
Eastern Steel Manufacturing Co.,Ltd not only improve product production and sales services, but also provide additional value-added services. As long as you need, we can complete your specific needs together.
Facility
Eastern Steel Manufacturing Co.,Ltd not only improve product production and sales services, but also provide additional value-added services. As long as you need, we can complete your specific needs together.
Projects
Many years of large-scale project experience in various fields（Oil & Gas, Construction, Power Energy, Marine & Offshore, Water Treatment, Exploration & Drilling Services, Pipeline & Petrochemical etc.）, professional project team is responsible from receiving until the end of the project.
Seamless mechanical tubing is designed for mechanical and engineering applications requiring strength, dimensional consistency, and good machinability. Manufactured to ASTM, JIS, and EN standards, it is available in a wide range of sizes for industrial equipment, hydraulic systems, and precision components.
Sizes: OD 10.3–762mm
Wall Thickness: 6–35mm
Length: 5.8/6/11.8/12m
Standard: ASTM A53, ASTM A519, ASTM A500, ASTM A252, JIS G3441/G3445, EN 10210/10297
Services: Cutting · Honing · Heat Treatment · Machining
1. Types of Mechanical Tubing
Manufactured without a longitudinal weld seam, seamless mechanical tubing offers dependable strength, dimensional consistency and machining reliability. It is widely used where higher structural integrity and stable mechanical performance are required for engineering and industrial applications.
DOM mechanical tubing is produced from electric resistance welded tubing and further processed through cold drawing to improve dimensional accuracy, concentricity and surface finish. DOM tubing is widely used in automotive components, hydraulic systems, rollers and precision mechanical parts requiring smoother internal and external surfaces.
ERW mechanical tubing is manufactured through electric resistance welding and is commonly used for general mechanical and structural applications. Compared with seamless tubing, ERW tubing offers cost advantages and stable dimensional control for applications where extremely high pressure resistance is not required.
Cold drawn seamless mechanical tubing is processed through cold drawing to achieve tighter dimensional tolerances, improved concentricity and smoother surface finish. This process is suitable for applications requiring higher machining precision and consistent mechanical performance, including hydraulic cylinders, precision machined parts and industrial equipment.
Features:
- Higher dimensional accuracy
- Smoother OD and ID surface
- Improved concentricity
- Better suitability for machining applications
Hot finished mechanical tubing is produced at elevated temperatures and is commonly used for larger diameters and heavier wall thickness applications. Compared with cold drawn tubing, hot finished tubing provides broader size availability and lower production cost for heavy-duty industrial applications.
Features:
- Larger diameter range
- Heavy wall thickness availability
- Lower production cost
- Suitable for structural and heavy-duty applications
Hydraulic cylinders require tubing with reliable pressure resistance, accurate dimensions and a smooth internal surface finish. Cold drawn and honed seamless mechanical tubing is widely used in construction machinery, industrial hydraulic systems and heavy equipment where consistent performance and long service life are required.
Seamless mechanical tubing is commonly used for bearing housings, bushings and other rotating components requiring dimensional consistency and dependable mechanical properties. The uniform tube structure supports machining accuracy and reliable operation in industrial equipment and power transmission systems.
Due to its good machinability and consistent wall thickness, mechanical tubing is frequently used to manufacture shafts, sleeves, spacers, couplings and other precision-machined parts. Stable material properties help improve machining efficiency and dimensional control during production.
Mechanical steel tubing is widely applied in automotive manufacturing for drive shafts, steering components, suspension systems, rollers and structural assemblies. Its combination of strength, dimensional precision and fabrication performance makes it suitable for a wide range of vehicle applications.
Construction and heavy-duty equipment require tubing capable of withstanding demanding operating conditions and continuous mechanical loads. Seamless mechanical tubing is commonly used in hydraulic assemblies, structural components and engineering machinery where strength, durability and fabrication performance are important.
| Standard | Description |
|---|---|
| ASTM A519 | Seamless carbon and alloy steel mechanical tubing |
| ASTM A500 | Structural tubing applications |
| ASTM A53 | General-purpose steel pipe |
| ASTM A252 | Structural piling pipe |
| JIS G3445 | Carbon steel tubes for machine structural use |
| EN 10297 | Seamless steel pipes for mechanical engineering |
| Project Specifications | Standards and material grades can be supplied according to project specifications and international requirements |
JIS G3445 Carbon steel pipes for machine structural use
EN 10297 Seamless steel tubes for mechanical engineering
Standards and material grades can be supplied according to project specifications and international requirements.
To reduce additional processing time and simplify project procurement, value-added processing services are available for seamless mechanical tubing based on customer requirements.
(1)Cutting
Custom cutting service available according to project length requirements and machining preparation.
(2)Honing
Honed tubing available for hydraulic cylinder applications requiring improved internal surface finish and dimensional accuracy.
(3)Heat Treatment
Normalizing, annealing, quenching and tempering services available for applications requiring specific mechanical properties.
(4)Machining
Additional machining services available for mechanical components and precision engineering applications.
(5)Chamfering
End chamfering service available to improve assembly efficiency and welding preparation.
(6)Surface Protection
Oiled, coated and export protective packaging available for long-distance transportation and storage protection.
Inspection and testing services are available according to project and customer requirements.
| Inspection Item | Available |
|---|---|
| Ultrasonic Testing (UT) | Yes |
| PMI Testing | Yes |
| Hydrostatic Testing | Yes |
| Eddy Current Testing | Yes |
| Mechanical Testing | Yes |
| Hardness Testing | Yes |
| Third-party Inspection | SGS / BV |
Dimensional tolerance data for cold drawn and hot finished seamless mechanical tubing is available below for engineering reference and project specification review.
Cold drawn seamless mechanical tubing---Diameter Tolerances
OD Size Range Inches,Inclusive
Wall Percent of OD
Quenched & Tempered
OD Size Range mm, Inclusive
Quenched & Tempered
OD
ID
OD & ID
Wall Percent of OD
OD
ID
OD & ID
Inches
Inches
± Inches
Inches
Inches
± Inches
Over
Under
Over
Under
Over
Under
Over
Under
0.500-1.699
All
0.005
0
0
0.005
0.015
12.70- 43.16
All
0.13
0
0
0.13
0.38
1.700-2.099
All
0.006
0
0
0.006
0.02
43.17- 53.32
All
0.15
0
0
0.15
0.51
2.100-2.499
All
0.007
0
0
0.007
0.023
53.33- 63.48
All
0.18
0
0
0.18
0.58
2.500-2.899
All
0.008
0
0
0.008
0.025
63.49- 73.64
All
0.2
0
0
0.2
0.64
2.900-3.299
All
0.009
0
0
0.009
0.028
73.65- 83.80
All
0.23
0
0
0.23
0.71
3.300-3.699
All
0.01
0
0
0.01
0.03
83.81- 93.96
All
0.25
0
0
0.25
0.76
3.700-4.099
All
0.011
0
0
0.011
0.033
93.97-104.12
All
0.28
0
0
0.28
0.84
4.100-4.499
All
0.012
0
0
0.012
0.036
104.13-114.28
All
0.3
0
0
0.3
0.91
4.500-4.899
All
0.013
0
0
0.013
0.038
114.29-124.44
All
0.33
0
0
0.33
0.97
4.900-5.299
All
0.014
0
0
0.014
0.041
124.45-134.60
All
0.36
0
0
0.36
1.04
5.300-5.549
All
0.015
0
0
0.015
0.044
134.61-140.95
All
0.38
0
0
0.38
1.12
5.550-5.999
Under 6
0.01
0.01
0.01
0.01
0.047
140.96-152.38
Under 6
0.25
0.25
0.25
0.25
1.19
6 to 7½
0.009
0.009
0.009
0.009
0.047
6 to 7½
0.23
0.23
0.23
0.23
1.19
Over 7½
0.018
0
0.009
0.009
0.047
Over 7½
0.46
0
0.23
0.23
1.19
6.000-6.499
Under 6
0.013
0.013
0.013
0.013
0.05
152.39-165.08
Under 6
0.33
0.33
0.33
0.33
1.27
6 to 7½
0.01
0.01
0.01
0.01
0.05
6 to 7½
0.25
0.25
0.25
0.25
1.27
Over 7½
0.02
0
0.01
0.01
0.05
Over 7½
0.51
0
0.25
0.25
1.27
6.500-6.999
Under 6
0.015
0.015
0.015
0.015
0.057
165.09-177.78
Under 6
0.38
0.38
0.38
0.38
1.45
6 to7½
0.012
0.012
0.012
0.012
0.053
6 to 7½
0.3
0.3
0.3
0.36
1.35
Over 7½
0.023
0
0.012
0.012
0.053
Over 7½
0.58
0
0.3
0.3
1.35
7.000-7.499
Under 6
0.018
0.018
0.018
0.018
0.065
177.79-190.48
Under 6
0.46
0.46
0.46
0.46
1.65
6 to 7½
0.013
0.013
0.013
0.013
0.056
6 to 7½
0.33
0.33
0.33
0.33
1.42
Over 7½
0.026
0
0.013
0.013
0.056
Over 7½
0.66
0
0.33
0.33
1.42
7.500-8.000
Under 6
0.02
0.02
0.02
0.02
0.07
190.49-203.20
Under 6
0.51
0.51
0.51
0.51
1.78
6 to 7½
0.015
0.015
0.015
0.015
0.06
6 to 7½
0.38
0.38
0.38
0.38
1.52
Over 7½
0.03
0
0.015
0.015
0.06
Over 7½
0.76
0
0.38
0.38
1.52
Wall Thickness Tolerance
| Wall Thickness (% of OD) | ≤ 38.07 mm ID | > 38.07 mm ID |
|---|---|---|
| Under 10% | ±10.0% | ±7.5% |
| 10% – 25% | ±10.0% | ±6.0% |
| Over 25% | ±12.5% | ±7.5% |
Hot-finished seamless mechanical tubing---Diameter Tolerances
| OD Size Range (in) | As Rolled / Annealed (± in) | Q&T (± in) | OD Size Range (mm) | As Rolled / Annealed (± mm) | Q&T (± mm) |
|---|---|---|---|---|---|
| 2.000–2.499 | 0.017 | 0.027 | 50.80–63.48 | 0.43 | 0.686 |
| 2.500–2.999 | 0.019 | 0.029 | 63.49–76.17 | 0.48 | 0.737 |
| 3.000–3.499 | 0.021 | 0.032 | 76.18–88.87 | 0.53 | 0.813 |
| 3.500–3.999 | 0.023 | 0.035 | 88.88–101.57 | 0.58 | 0.889 |
| 4.000–4.499 | 0.025 | 0.038 | 101.58–114.28 | 0.64 | 0.965 |
| 4.500–4.999 | 0.027 | 0.041 | 114.29–126.97 | 0.69 | 1.041 |
| 5.000–5.499 | 0.029 | 0.044 | 126.98–139.67 | 0.74 | 1.118 |
| 5.500–5.999 | 0.031 | 0.047 | 139.68–152.38 | 0.79 | 1.194 |
| 6.000–6.499 | 0.033 | 0.050 | 152.39–165.08 | 0.84 | 1.270 |
| 6.500–6.999 | 0.035 | 0.053 | 165.09–177.78 | 0.89 | 1.346 |
| 7.000–7.499 | 0.037 | 0.056 | 177.79–190.48 | 0.94 | 1.422 |
Wall Thickness Tolerance
| Wall Thickness (% of OD) | OD < 50.08 mm | OD ≥ 50.08 mm |
|---|---|---|
| Under 10% | ±10.0% | ±7.5% |
| 10% – 25% | ±7.5% | ±7.5% |
Q1: What is seamless mechanical tubing?
Seamless mechanical tubing is steel tubing manufactured without a welded seam for applications requiring reliable mechanical strength, dimensional accuracy and machining performance. It is widely used for hydraulic cylinders, shafts, bearings and industrial machinery components.
Q2: What is the difference between seamless tubing and DOM tubing?
Seamless tubing is produced without welding and is commonly used for higher-pressure and heavy-duty mechanical applications. DOM tubing is manufactured from ERW tubing and further cold drawn to improve dimensional accuracy, concentricity and surface finish.
Q3: What tubing is commonly used for hydraulic cylinders?
Cold drawn seamless tubing and honed tubing are commonly used for hydraulic cylinder applications requiring smooth internal surface finish, dimensional precision and reliable pressure resistance.
Q4: Can seamless mechanical tubing be machined?
Yes. Seamless mechanical tubing is widely used for machining applications including sleeves, bushings, rollers, shafts and precision mechanical components requiring stable mechanical properties and good machinability.
Q5: Is heat treatment available for mechanical tubing?
Heat treatment services including normalizing, annealing, quenching and tempering are available according to project and mechanical property requirements.
Q6: Is third-party inspection available?
Third-party inspection services including SGS and BV inspection support are available according to project requirements.
E-mail: sales@eastern-steels.com
