Black steel pipe, also referred to as carbon steel pipe, mild steel pipe, is a type of piping made from low-carbon steel. Its distinctive dark appearance comes from a black oxide scale that forms on its surface during manufacturing.
Typically, black steel pipes are unprocessed round pipes, primarily treated for surface finish. Due to the absence of a protective coating, they are more prone to corrosion, making them suitable for use in dry environments or where they can be painted or otherwise protected. Known for their strength and durability, black steel pipes are a popular choice for both residential and industrial applications. They come in various sizes and thicknesses, providing versatility for different construction and installation needs.
1. Brief Introduction on Black Steel Pipes
| Product | Black Steel Pipe |
| Material | Low Carbon Steel |
| Grade | Q195 = S195 / A53 Grade A
Q235 = S235 / A53 Grade B / A500 Grade A Q355 = S355JR / A500 Grade B Grade C |
| Standard | GB/T3091, GB/T13793API 5L/ASTM A53, A500, A36, ASTM A795 |
| Specifications | ASTM A53 A500 sch10 – sch80 |
| Surface | Painted Black or Natural Black |
| Ends | Plain ends |
| Beveled ends | |
| Grooved ends |
| ASTM A53 Type E | Chemical Composition | Mechanical Properties | |||||
| Steel grade | C (max.)% | Mn (max.)% | P (max.)% | S (max.)% | Yield strength min. MPa |
Tensile strength min. MPa |
|
| Grade A | 0.25 | 0.95 | 0.05 | 0.045 | 205 | 330 | |
| Grade B | 0.3 | 1.2 | 0.05 | 0.045 | 240 | 415 | |
| Chemical composition | Mechanical properties, WT≤16mm | ||||||||
| Standard | Steel grade | C (max.)% | Si (max.)% | Mn (max.)% | P (max.)% | S (max.)% | Minimum yield strength MPa |
Tensile strength MPa |
Minimum elongation % |
| GB/T 700-2006 | Q235A | 0.22 | 0.35 | 1.4 | 0.045 | 0.05 | 235 | 370-500 | 26 |
| GB/T 700-2006 | Q235B | 0.2 | 0.35 | 1.4 | 0.045 | 0.045 | 235 | 370-500 | 26 |
| DN | OD | ASTM A53 GRA / B | ASTM A795 GRA / B | |||
| SCH10S | STD SCH40 | SCH10 | SCH30 SCH40 | |||
| MM | INCH | MM | (mm) | (mm) | (mm) | (mm) |
| 15 | 1/2” | 21.3 | 2.11 | 2.77 | - | 2.77 |
| 20 | 3/4” | 26.7 | 2.11 | 2.87 | 2.11 | 2.87 |
| 25 | 1” | 33.4 | 2.77 | 3.38 | 2.77 | 3.38 |
| 32 | 1-1/4” | 42.2 | 2.77 | 3.56 | 2.77 | 3.56 |
| 40 | 1-1/2” | 48.3 | 2.77 | 3.68 | 2.77 | 3.68 |
| 50 | 2” | 60.3 | 2.77 | 3.91 | 2.77 | 3.91 |
| 65 | 2-1/2” | 73 | 3.05 | 5.16 | 3.05 | 5.16 |
| 80 | 3” | 88.9 | 3.05 | 5.49 | 3.05 | 5.49 |
| 90 | 3-1/2" | 101.6 | 3.05 | 5.74 | 3.05 | 5.74 |
| 100 | 4” | 114.3 | 3.05 | 6.02 | 3.05 | 6.02 |
| 125 | 5” | 141.3 | 3.4 | 6.55 | 3.4 | 6.55 |
| 150 | 6” | 168.3 | 3.4 | 7.11 | 3.4 | 7.11 |
| 200 | 8” | 219.1 | 3.76 | 8.18 | 4.78 | 7.04 |
| 250 | 10” | 273.1 | 4.19 | 9.27 | 4.78 | 7.8 |
2. Different types of black steel pipes
According to different production processes, black steel pipes are mainly divided into welded steel pipes and seamless steel pipes.
Welded Steel Pipe: Welded steel pipe is made by welding steel plates or strips rolled into a tube. It is also known as ERW (Electric Resistance Welded) pipe. This type of pipe usually has good strength and toughness. The production process of welded steel pipe is relatively simple, and it can produce longer pipe sections at a lower cost.
Seamless Steel Pipe: Seamless steel pipe is manufactured through hot or cold rolling process without welded seams. This kind of pipe has higher strength and safety under high pressure and extreme conditions because it has no weak points (such as welds).
3. What is black steel pipe for?
Black pipe is widely used in various applications, including plumbing, gas distribution, and structural support.
Seamless steel pipe is manufactured without any seams or welds, which enhances its strength and makes it a safer option for transporting gases and fluids under high pressure. This type of pipe is particularly valued in applications where structural integrity is critical, such as in oil and gas pipelines.
On the other hand, black welded steel pipe is commonly used in various applications, including water pipes, gas transmission and fire sprinkler systems. Its fire-resistant properties make it suitable for such systems, where reliability and safety are paramount.
4. Black Pipes Quality Control And Delivery
1) During and after production, QC staffs with more than 5 years experience inspect products in random.
2) National accredited laboratory with CNAS certificates
3) Acceptable inspection from third party appointed/paid by buyer, such as SGS, BV.
4) Approved by Malaysia, Indonesia, Singapore, Philippines, Australia, Peru and UK. We own UL /FM, ISO9001/18001, FPC certificates.
Packing and Delivery:
Packing Details : in hexagonal seaworthy bundles packed by steel strips, With two nylon slings for each bundles.
Delivery Details : Depending on the QTY, normally 20-30 days.
Delivery Port: TIANJIN PORT IN CHINA
Payment:
Payment Method: Advance TT, T/T, L/C, OA.
Trade Terms: FOB , CIF , CFR, FCA
Primary Competitive Advantage:
- Small Orders Accepted Brand-name Parts Country of Origin
- Experienced Staff Form A Guarantee/Warranty
- International Approvals Packaging
- Factory Price Product Features Product Performance
- Prompt Delivery Quality Approvals Reputation
- Service Sample Available
Main Export Markets
- Southeast Asia
- Australia
- Middle East
- Africa
- North Asia
- Central/South America
