The Most Reliable Supplier of Stainless Steel Pipes — GNEE
GNEE is a professional supplier of austenitic stainless steel, super austenitic stainless steel, duplex steel, super duplex steel, and other advanced materials. With over 18 years of export experience, we offer a wide range of products, including seamless pipes, welded pipes, precision tubes, and customized profile tubes.
Our factory is equipped with advanced cold rolling, cold drawing, and automatic welding production lines, with an annual production capacity of over 1,0000 tons. We can supply a full range of specifications with outer diameters from 6mm to 219mm and wall thicknesses from 0.5mm to 20mm. All products are manufactured in strict accordance with international standards such as ASTM, AISI, JIS, DIN, and EN, and are certified by ISO 9001, SGS, and BV. This ensures stable chemical composition, high dimensional accuracy, and excellent corrosion resistance performance.
We specialize in the production and supply of high-performance stainless steel pipes, covering materials such as austenitic stainless steel (304/304L, 316/316L, 321), super austenitic stainless steel (904L), duplex stainless steel (2205, 2507), and other special alloy materials to meet the needs of various corrosive environments and engineering projects.
Stainless steel seamless pipe and welded pipe production process
In terms of production processes, seamless pipes employ a piercing-hot/cold rolling-cold drawing-solution treatment-pickling and passivation process to ensure dense microstructure, high strength, and excellent pressure resistance. Welded pipes utilize an automated TIG welding-online solution treatment-eddy current/ultrasonic testing-hydraulic pressure testing process to ensure uniform and stable welds with no leakage risk. Product outer diameter ranges from 6mm to 219mm, wall thickness from 0.5mm to 20mm, and dimensional tolerances are controlled within ±0.05mm, meeting the requirements of high-precision industrial applications.
producing process of stainless steel seamless pipe
producing process of stainless steel welded pipe
All products are manufactured according to international standards such as ASTM, AISI, JIS, DIN, and EN, and have passed certification systems such as ISO 9001, SGS, and BV.
Stainless Steel Pipes Dimensions and Weights
Stainless steel pipe dimension as per astm & weight
Nominal
Outside Diameter
Sch 5S
Sch 10S
Sch-40S
Sch-80S
Sch-160S
Sch-XXS
mm
inch
mm
WT mm
Weight (Kg/mt)
WT mm
Weight (Kg/mt)
WT mm
Weight (Kg/mt)
WT mm
Weight (Kg/mt)
WT mm
Weight (Kg/mt)
WT mm
Weight (Kg/mt)
3
1/8
10.3
1.24
0.276
1.24
0.28
1.73
0.37
2.41
0.47
-
-
-
-
6
1/4
13.7
1.24
0.390
1.65
0.49
2.24
0.631
3.02
0.80
-
-
-
-
10
3/8
17.1
1.24
0.490
1.65
0.63
2.31
0.845
3.20
1.10
-
-
-
-
15
1/2
21.3
1.65
0.800
2.11
1.00
2.77
1.27
3.75
1.62
4.75
1.94
7.47
2.55
20
3/4
26.7
1.65
1.03
2.11
1.28
2.87
1.68
3.91
2.20
5.54
2.89
7.82
3.63
25
1
33.4
1.65
1.30
2.77
2.09
3.38
2.50
4.55
3.24
6.35
4.24
9.09
5.45
32
1 1/4
42.2
1.65
1.65
2.77
2.70
3.56
3.38
4.85
4.47
6.35
5.61
9.70
7.77
40
1 1/2
48.3
1.65
1.91
2.77
3.11
3.68
4.05
5.08
5.41
7.14
7.25
10.16
9.54
50
2
60.3
1.65
2.40
2.77
3.93
3.91
5.44
5.54
7.48
8.74
11.1
11.07
13.44
65
2 1/2
73.0
2.11
3.69
3.05
5.26
5.16
8.63
7.01
11.4
9.53
14.9
14.2
20.39
80
3
88.9
2.11
4.51
3.05
6.45
5.49
11.30
7.62
15.2
11.1
21.3
15.24
27.65
100
4
114.3
2.11
5.84
3.05
8.36
6.02
16.07
8.56
22.3
13.49
33.54
17.12
41.03
125
5
141.3
2.77
9.47
3.40
11.57
6.55
21.8
9.53
31.97
15.88
49.11
19.05
57.43
150
6
168.3
2.77
11.32
3.40
13.84
7.11
28.3
10.97
42.7
18.2
67.56
21.95
79.22
200
8
219.1
2.77
14.79
3.76
19.96
8.18
42.6
12.7
64.6
23.0
111.2
22.23
107.8
250
10
273.1
3.40
22.63
4.19
27.78
9.27
60.5
12.7
96.0
28.6
172.4
25.40
155.15
300
12
323.9
3.96
31.25
4.57
36.00
9.52
73.88
12.7
132.0
33.32
238.76
25.40
186.97
350
14
355.6
3.96
34.36
4.78
41.3
11.13
94.59
19.05
158.08
35.71
281.70
-
-
400
16
406.4
4.19
41.56
4.78
47.29
12.7
123.30
21.41
203.33
40.46
365.11
-
-
450
18
457.2
4.19
46.80
4.78
53.42
14.27
155.80
23.8
254.36
45.71
466.40
-
-
500
20
508.0
4.78
59.25
5.54
68.71
15.09
183.42
26.19
311.2
49.99
564.68
-
-
600
24
609.6
5.54
82.47
6.35
94.45
17.48
255.41
30.96
442.08
59.54
808.22
-
-
Weight & thickness of S.S guage pipes
Dimension
10 SWG(3.2MM)
12 SWG(2.6MM)
14 SWG(2.1MM)
16 SWG(1.65MM)
18 SWG (1.2MM)
19 SWG(1.0MM)
Size
OD
Weight/MTR
Weight/MTR
Weight/MTR
Weight/MTR
Weight/MTR
Weight/MTR
1/2"
12.7
0.754
0.651
0.552
0.452
0.342
0.290
5/8"
15.875
1.006
0.856
0.718
0.582
0.437
0.369
3/4"
19.05
1.258
1.061
0.883
0.712
0.531
0.448
1"
25.4
1.762
1.470
1.214
0.972
0.720
0.605
1 1/4"
31.75
2.266
1.880
1.544
1.232
0.909
0.763
1 1/2"
38.1
2.770
2.289
1.875
1.492
1.098
0.920
2"
50.8
3.778
3.108
2.537
2.012
1.476
1.235
2 1/2"
63.5
4.786
3.928
3.198
2.531
1.854
1.550
3"
76.2
5.794
4.747
3.860
3.051
2.232
1.865
3 1/2"
88.9
6.802
5.566
4.521
3.571
2.610
2.180
4"
101.6
7.810
6.385
5.183
4.091
2.988
2.495
How to calculate the weight of a Stainless Steel Round Pipe?
OD (Outside Diameter): Outer Diameter (mm)
WT (Wall Thickness): Wall Thickness (mm)
Constant (Coefficient):
0.02491 (Applicable to 201, 304, 304L, 321 materials)
0.02507 (Applicable to 316, 316L, 310S materials)
(Example: A 304 pipe with 50mm OD and 2mm WT: (50-2) × 2 × 0.02491 = 2.39 kg/m)
Stainless steel pipe surface treatment
(Standard Industrial Finishes)
This type of surface is mainly used in industrial pipes and structural components, emphasizing corrosion resistance.
Finish Name
Code
Description
Roughness (Ra)
Typical Applications
No. 1
Hot Rolled
Hot rolled, annealed, and pickled (descaled). Dull, rough surface.
> 2.0 μm
Industrial tanks, chemical piping, structural parts.
2B
Cold Rolled
Cold rolled, heat treated, pickled, and passed through polished rollers. Smooth and slightly reflective.
0.1 - 0.5 μm
Food processing, medical equipment, general hardware.
BA
Bright Annealed
Cold rolled and annealed in a controlled atmosphere furnace to retain a highly reflective finish.
< 0.1 μm
Kitchenware, dairy equipment, automotive trim.
2D
Cold Rolled
Cold rolled, annealed, and pickled. A uniform, dull silver-gray finish.
0.5 - 1.0 μm
Automotive exhaust systems, drainage pipes.
(Mechanical & Decorative Finishes)
These surfaces are processed by physical grinding and are mainly used for aesthetic or specific hygiene requirements.
Finish Name
Grit/Standard
Description
Satin / Brushed
180# - 240#
Achieved by polishing with fine abrasive belts. Non-reflective, unidirectional texture.
No. 4
150# - 180#
A general-purpose polished finish with visible short, parallel grit lines.
Hairline (HL)
Continuous Grit
Long, continuous, and fine polishing lines extending along the length of the pipe.
Mirror (8K)
600# - 800#
The highest level of polishing. Removes all surface defects to create a mirror-like reflection.
Sandblasted
Bead Blast
Surface treated with glass beads or steel shot to create a uniform, non-directional matte finish.
Our stainless steel pipe export cases
Our stainless steel pipe export portfolio fully demonstrates our strong global delivery capabilities and consistent product performance. With over 18 years of export experience, we have supplied more than 30,000 tons of stainless steel pipes to over 50 countries and regions in Europe, the Middle East, Southeast Asia, and South America. Our projects cover key industries such as chemical engineering, heat exchange systems, pressure vessels, desalination plants, and marine engineering.
GNEE Stainless Steel boasts a 5,000-square-meter indoor warehouse, effectively protecting against environmental corrosion.
In-stock inventory: Over 10,00 tons of standard specifications (304, 316L, 310S) steel pipes are available for immediate shipment.
Wide product range: Covering steel pipes from Sch 5S to Sch XXS specifications, and various diameters (6 mm to 630 mm).
Lead Time
Category
Lead Time
Logistics
Stock Items
4 - 7 Days
Fast loading & dispatch to port.
Standard Production
10 - 15 Days
Efficient scheduling with weekly updates.
Customized / OEM
20 - 30 Days
Full process tracking from raw material to finish.
Stainless steel pipe factory
Stainless steel pipe inventory
Quality Control & Testing
Raw Material Test: 100% PMI (Positive Material Identification) to ensure chemical composition.
In-Process Test: Eddy Current and Ultrasonic Testing (UT) to detect internal defects.
Pressure Test: 100% Hydrostatic testing according to international standards.
Dimension Check: Precise measurement of OD, WT, and Length with calibrated tools.
Documentation: Provide MTC (Mill Test Certificate) to EN 10204 3.1 for every batch.
From raw material spectral analysis to water pressure testing and flaw detection before leaving the factory, we ensure that every pipe meets international standards and provides a 3.1 material certificate with the shipment.
100% PMI (Positive Material Identification)
100% Hydrostatic testing
Professional Packaging and Loading
For long-distance transportation, especially by sea, you need to pay attention to detail and properly protect your products to eliminate the risk of damage during transit.
End Protection: Use plastic caps or wooden plugs to protect the pipe threads at both ends and ensure the inside of the pipe is clean.
Surface Protection: Each pipe is individually bundled in a plastic bag (for polished pipes) or woven bag.
Packaging Options:
Standard Packaging: Steel strapping bundled into a hexagonal shape.
Advanced Packaging: Thin-walled/high-precision pipes are packaged in reinforced wooden crates or iron frames suitable for sea transport.
Safe Loading: Professional strapping and supports are used inside the container to prevent movement during sea transport.
316 316L Stainless steel packaging .video
Stainless steel pipe plastic packaging
Stainless steel pipe wooden crate packaging
Value-added Services
We not only provide pipes, but also elbows, flanges, and valves, and offer solutions for precision pipes and custom-made non-standard pipes. We also provide additional services such as laser cutting, bending, flaring, necking, welding, and tapping.
Stainless Steel Pipe Polishing
Stainless Steel Pipe Beveling
Heat treating & Annealing
UT Testing
Stainless Steel Pipe Cutting
Stainless Steel Tube Bending
FAQ
Q: What is the difference between 304 and 316 stainless steel pipes?
A: 304 is the most common grade with excellent corrosion resistance for general use. 316 contains added Molybdenum, making it superior for highly corrosive environments like marine, chemical, or pharmaceutical industries.
Q: Which international standards do your pipes follow?
A: Our pipes are manufactured strictly according to ASTM A312, A213, A269 (for US standards) and EN 10216-5, EN 10217-7 (for European standards). We ensure full compliance with the requested technical specifications.
Q: What is the tolerance for your pipe diameter and wall thickness?
A: Our standard tolerance follows ASTM A312. For high-precision requirements, we can control the outside diameter (OD) within ±0.05mm and wall thickness (WT) within ±0.02mm.
Q: How long will it take to receive my order?
A: For stock items, we dispatch within 48 hours. For production orders, the lead time is usually 7-15 days for standard sizes and 20-30 days for customized specifications or large quantities.
Q: Can I get a sample before placing a large order?
A: Yes, we provide free samples (typically 10-20cm long). You only need to cover the international shipping cost, which will be deducted from your first formal order.
Q: Do you support third-party inspections like SGS or BV?
A: Yes, we fully support and welcome third-party inspections (SGS, BV, TUV, Intertek). We will cooperate with their inspectors to ensure all data meets your requirements before loading.
Q: Will the stainless steel pipe rust during sea transportation?
A: No. We use high-quality raw materials and professional pickling/passivation treatments to enhance corrosion resistance. Additionally, we use moisture-proof packaging to ensure the pipes remain in perfect condition during long sea transit.
Q: What happens if there is a quality issue after I receive the goods?
A: We take full responsibility for our quality. If the material or specifications do not match the contract, we offer a full refund or free replacement within 30 days of arrival.
We're professional stainless steel pipe manufacturers and suppliers in China, specialized in providing high quality customized service. Be free to wholesale stainless steel pipe in stock here and get free sample from our factory. For price consultation, contact us.
