SCH 40 black steel pipe refers to carbon steel pipe with standard wall thickness in its original unfinished state. Covered with iron oxide scale on the surface, it appears black and acts as the base material for coated steel pipes.
It complies with ASME B36.10 standard, compatible with mainstream international specifications including ASTM A53 Gr.B, ASTM A106 and so on, and matches most standard pipe fittings perfectly. Low price and universal dimensional compatibility are its prominent advantages.
As a top-tier manufacturer of SCH 40 black steel pipe, Glory Steel specializes in the production of seamless and welded SCH 40 black steel pipes. Custom cutting and various processing services are available.
Specifications
| Item | Details |
|---|---|
| Product | Schedule 40 Black Steel Pipe |
| MOQ | 10 Tons |
| Material | SS400, STK400, S275JR, Q235B, ASTM A53 Gr.B |
| Outer Diameter | 21.3mm~323.8mm, 1/2″~12″ |
| Length | 1-12m |
| Wall Thickness | SCH40 standard |
| Package | Standard export packaging |
| Surface Treatment | Bare pipe, oil coating, painting, galvanizing, etc. |
Advantages
Stable Pressure Resistance
It boasts reliable mechanical strength, which guarantees safe delivery of compressed air, medium- and low-pressure liquids, fuel oil, and other media.
Superior Machinability
It has excellent welding performance. Serving as the blank tube for galvanized pipes and PE pipes, it supports efficient threading and bending without limitations during post-processing.
Cost-Effective
It is the most affordable steel pipe in the market, delivering outstanding cost performance for bulk orders.
Globally Unified Specifications
SCH40 is the standard wall thickness (STD) under the NPS system. The unified wall thickness is well compatible with fittings for global projects.
Application Scope
- Fluid Transportation: Long-distance pipelines for oil, natural gas, coal gas, and low-pressure water conveyance.
- Building Structure: Raw material for scaffolding, steel structure frames and equipment bases.
- Municipal & Agricultural Projects: Water conservancy and irrigation pipelines, fence posts.
Pressure Rating
| NPS Nominal Size | OD(inch/mm) | SCH40 Wall(inch/mm) | Working Pressure PSI(Bar) | Burst Pressure PSI(Bar) |
|---|---|---|---|---|
| 1/2″ | 0.840″ / 21.3 mm | 0.109″ / 2.77 mm | 1480 psi (102.1 bar) | 5920 psi (408.2 bar) |
| 3/4″ | 1.050″ / 26.9 mm | 0.113″ / 2.87 mm | 1260 psi (86.9 bar) | 5040 psi (347.5 bar) |
| 1″ | 1.315″ / 33.4 mm | 0.133″ / 3.38 mm | 1140 psi (78.6 bar) | 4560 psi (314.4 bar) |
| 2″ | 2.375″ / 60.3 mm | 0.154″ / 3.91 mm | 1000 psi (68.9 bar) | 4000 psi (275.8 bar) |
| 3″ | 3.500″ / 88.9 mm | 0.216″ / 5.49 mm | 860 psi (59.3 bar) | 3440 psi (237.2 bar) |
| 4″ | 4.500″ / 114.3 mm | 0.237″ / 6.02 mm | 720 psi (49.6 bar) | 2880 psi (198.6 bar) |
| 6″ | 6.625″ / 168.3 mm | 0.280″ / 7.11 mm | 600 psi (41.4 bar) | 2400 psi (165.5 bar) |
| 8″ | 8.625″ / 219.1 mm | 0.322″ / 8.18 mm | 520 psi (35.9 bar) | 2080 psi (143.4 bar) |
| 10″ | 10.750″ / 273.1 mm | 0.365″ / 9.27 mm | 460 psi (31.7 bar) | 1840 psi (126.9 bar) |
| 12″ | 12.750″ / 323.9 mm | 0.406″ /10.31 mm | 410 psi (28.3 bar) | 1640 psi (113.1 bar) |
Based on A53 Grade B / ASME B31.1, ASME B36.10M, carbon steel black pipe, operating pressure for plain‑end welded installation (safety factor 8:1, ambient temperature 100°F / 38℃)
Note: Pressure rating drops when temperature rises; threaded ends reduce pressure capacity significantly.
Classification of SCH 40 Black Steel Pipe
1. Classification by Production Technology
- Seamless SCH 40 Black Steel Pipe: No weld seam on the whole pipe with uniform material. Manufactured from round steel billets via hot rolling or cold drawing.
- Welded SCH 40 Black Steel Pipe: Comes with a weld seam. Produced from hot rolled steel strips through cold forming and electric resistance welding.
2. Classification by Pipe End Form
| Type | Description | Applicable Connection Method |
|---|---|---|
| Plain End (PE) | Vertically cut ends without threads | Weld connection, grooved connection |
| Threaded End (TE) | Ends processed with NPT or BSPT tapered threads | Threaded connection |
| Beveled End (BE) | Ends with 30°±5° bevel | Butt welding (for heavy-wall pipes) |
3. Classification by Usage
- Fluid Transportation SCH40 Black Pipe: Meets ASTM A53 / GB/T 3091 / GB/T 8163, used for water, gas and oil delivery.
- Structural SCH40 Black Pipe: Complies with ASTM A53 / GB/T 8162 / JIS G3444, applied for building frames, vehicle brackets, and mechanical equipment supports.
- Fire Protection SCH40 Black Pipe: The base material for fire sprinkler pipelines, which requires subsequent hot-dip galvanizing.
SCH40 Black Steel Pipe vs SCH40 Galvanized Steel Pipe
| Comparison Item | SCH40 Black Steel Pipe | SCH40 Galvanized Steel Pipe |
|---|---|---|
| Surface | Black iron oxide film | Silvery zinc coating |
| Anti-corrosion | Basic rust prevention | Long-term anti-corrosion |
| Welding Operation | Direct welding available | Zinc layer needs polishing before welding |
| Price | Low | Medium (20%~40% higher) |
| Post Treatment | Can be galvanized or painted | No further anti-rust treatment needed |
NPS 1/2″~12″ SCH40 Dimension Table
| NPS | DN | OD (mm) | SCH40 WT (mm) | Theoretical Weight (kg/m) |
|---|---|---|---|---|
| 1/2″ | DN15 | 21.3 | 2.77 | 1.27 |
| 3/4″ | DN20 | 26.7 | 2.87 | 1.68 |
| 1″ | DN25 | 33.4 | 3.38 | 2.51 |
| 1 1/4″ | DN32 | 42.2 | 3.56 | 3.38 |
| 1 1/2″ | DN40 | 48.3 | 3.68 | 4.05 |
| 2″ | DN50 | 60.3 | 3.91 | 5.29 |
| 2 1/2″ | DN65 | 76.1 | 5.16 | 7.87 |
| 3″ | DN80 | 88.9 | 5.49 | 9.82 |
| 4″ | DN100 | 114.3 | 6.02 | 16.07 |
| 6″ | DN150 | 168.3 | 7.11 | 22.89 |
| 8″ | DN200 | 219.1 | 8.18 | 34.03 |
| 10″ | DN250 | 273.0 | 9.27 | 47.62 |
| 12″ | DN300 | 323.8 | 10.31 | 61.56 |
Why Choose Us
- Strict Quality Control: Layer-by-layer inspection on wall thickness tolerance and pressure resistance; dual production lines for seamless & welded pipes, full sizes in stock.
- One-Stop Custom Service: Cutting, threading, beveling, painting, hot-dip galvanizing and other pre-processing are all available.
- Professional Technical Support: We provide suggestions on pressure selection, length planning and wall thickness matching based on your actual usage.
- Factory Direct Price: No intermediate markup; tiered discounts for full container orders. Real-time order update and traceable logistics.
Glory Steel factory, located in Tianjin, China, is an ISO 9001, ISO 14001, and CE-certified factory with an annual output of 100,000 tons. We specialize in manufacturing SCH40/SCH80 Black Carbon Pipes and galvanized tubing in popular diameters such as 1/2”-6”, and offer full customization services. With our high-quality products and services, we export to over 120 countries.
