The 6-inch ASTM A312 TP304 SCH 10S stainless steel pipe is a thin-wall austenitic stainless steel pipe manufactured according to ASTM International ASTM A312 specification. TP304 is widely used for general-purpose corrosion-resistant piping, chemical process lines, and low-pressure heat transfer applications.
Schedule 10S (SCH 10S) indicates a thinner wall suitable for low to medium pressure systems while maintaining excellent corrosion resistance and weldability.
Material & Standard Information
Specification: ASTM A312 / A312M
Grade: TP304 (UNS S30400)
Schedule: SCH 10S
Nominal Pipe Size (NPS): 6 inch
OD (Outside Diameter): 168.28 mm (6.625")
Manufacturing Type: Seamless (SMLS) / Welded (ERW / EFW)
Inspection Certificates: EN 10204 3.1 / 3.2 available
TP304 is a versatile stainless steel grade offering good corrosion resistance in non-chloride environments, mild chemicals, and atmospheric exposure.
6" SCH 10S Pipe Dimensions & Weight
| Nominal Pipe Size (NPS) | Outside Diameter (OD) | Wall Thickness (SCH 10S) | Inside Diameter (Approx.) | Weight per Meter | Weight per Foot |
|---|---|---|---|---|---|
| 6" | 168.28 mm (6.625") | 3.05 mm (0.120") | 162.18 mm | 10.72 kg/m | 7.18 lb/ft |
Notes:
Dimensions follow ASME B36.19M for stainless steel pipes.
Weight is calculated for seamless pipes; welded pipes may vary slightly.
Chemical Composition of TP304
| Element | Composition (%) |
|---|---|
| C | ≤ 0.08 |
| Cr | 18.0 – 20.0 |
| Ni | 8.0 – 11.0 |
| Mn | ≤ 2.0 |
| Si | ≤ 1.0 |
| P | ≤ 0.045 |
| S | ≤ 0.030 |
TP304 provides good corrosion resistance in atmospheric, mild chemical, and food-grade environments.
Mechanical Properties (Minimum)
| roperty | Value |
|---|---|
| Tensile Strength | 515 MPa |
| Yield Strength | 205 MPa |
| Elongation | 40% |
| Hardness | ≤ 217 HB |
TP304 maintains excellent formability, weldability, and durability in low-pressure piping systems.
Typical Applications
Low-pressure process piping
Heat exchangers
Water supply and drainage lines
Food & beverage process systems
HVAC and ventilation piping
Notes on SCH 10S
SCH 10S is considered a thin-wall schedule, suitable for low-pressure service.
For higher pressure applications, SCH 40S or SCH 80S is recommended.
TP304 does not contain molybdenum; for chloride-rich environments, consider TP316 or TP316L.
FAQ
1️⃣ What is 6" ASTM A312 TP304 SCH 10S stainless steel pipe?
It is a 6-inch nominal diameter austenitic stainless steel pipe manufactured according to ASTM International ASTM A312 specification. SCH 10S indicates a thin-wall pipe suitable for low-pressure applications, while TP304 provides general corrosion resistance and excellent weldability.
2️⃣ What does Schedule 10S mean?
Schedule 10S (SCH 10S) defines a thin wall thickness for stainless steel pipes under ASME B36.19M.
For a 6" pipe:
Wall thickness: 3.05 mm (0.120")
Suitable for low-pressure systems
Reduces weight and material cost compared to SCH 40S or SCH 80S
3️⃣ What are the typical applications of 6" SCH 10S TP304 pipe?
Low-pressure process piping
Heat exchangers
Water supply and drainage systems
HVAC systems
Food and beverage process lines
4️⃣ How does TP304 differ from TP316 for stainless steel pipes?
TP304: General corrosion resistance, no molybdenum
TP316 / 316L: Contains molybdenum, higher resistance to chlorides and pitting
For mild chemical or atmospheric conditions, TP304 is sufficient; for seawater or aggressive chloride environments, TP316/316L is recommended
5️⃣ Can 6" TP304 SCH 10S be welded easily?
Yes. TP304 is highly weldable using standard TIG, MIG, or arc welding methods. Post-weld passivation is recommended for critical applications to restore corrosion resistance.
6️⃣ Is 6" SCH 10S suitable for high-pressure systems?
No. SCH 10S is designed for low-pressure service. For higher pressures, SCH 40S or SCH 80S should be used. Always check the design pressure against ASME B31.3 or B31.1 piping codes.
7️⃣ What inspection certificates are typically provided?
EN 10204 3.1 Mill Test Certificate (MTC)
Chemical composition report
Mechanical property report
Hydrostatic test report
Ultrasonic or radiographic testing if specified
Third-party inspection (SGS / BV / TUV)
Full heat number traceability is standard for industrial and EPC projects.
8️⃣ What is the corrosion resistance of TP304 SCH 10S?
Good resistance in atmospheric and mild chemical environments
Resistant to oxidizing agents
Not suitable for strong chlorides or seawater exposure; TP316L is recommended in such cases
9️⃣ What is the difference between seamless and welded 6" TP304 SCH 10S pipes?
| Type | Recommended Use |
|---|---|
| Seamless | High-quality, uniform wall thickness, better pressure rating |
| Welded | Economical, suitable for general low-pressure systems |
For SCH 10S, both types are available, but seamless is preferred for higher integrity projects.
🔟 How to select a reliable TP304 pipe supplier?
Ensure ASTM A312 compliance
Verify dimensional accuracy per ASME B36.19M
Check chemical and mechanical certificates
Ensure heat number traceability
Confirm experience with industrial or EPC projects
Confirm third-party inspection support if required
