ASTM B407 / ASME SB407 is the standard specification by ASTM International covering Nickel-Iron-Chromium alloy seamless pipe and tube, including UNS N08800 (Incoloy 800), N08810 (Incoloy 800H), N08811 (Incoloy 800HT), and N08120 (HR-120). The specification covers cold-worked and hot-finished annealed conditions. These alloys are austenitic iron-nickel-chromium materials with excellent resistance to oxidation and carburization at elevated temperatures, widely used in petrochemical crackers, steam reformers, furnace components, and heat exchangers.
Zhengzhou Huitong (HT Pipe) supplies ASTM B407 seamless pipe and tube in all specified grades with full Mill Test Certificates (MTC) per EN 10204 3.1 and grain size certifications.
1. Standard Scope & Designation
ASTM B407 covers Nickel-Iron-Chromium alloys in the form of cold-worked and hot-finished annealed seamless pipe and tube. Alloys N08800 and N06811 are primarily for general corrosion service; N08810, N08811, and N08120 are specifically qualified for high-temperature creep-rupture service with mandatory grain size requirements.
| Designation |
Issuing Body |
Common Name |
Latest Edition |
| ASTM B407 |
ASTM International |
Incoloy 800 / 800H / 800HT / HR-120 |
B407-22 |
| ASME SB407 |
ASME (Section II Part B) |
Identical to ASTM B407 |
ASME SB407-2023 |
Scope Statement (ASTM B407-22): "This specification covers UNS N08120, UNS N08800, UNS N08801, UNS N08810, UNS N08811, UNS N08890, and UNS N06811 in the form of cold-worked and hot-finished annealed seamless pipe and tube. Alloys UNS N08800 and N06811 are primarily intended for general corrosive service. Alloys UNS N08810, N08811, and N08120 are intended for high-temperature service."
| Parameter |
Description |
Notes |
| Product Forms |
Seamless Pipe, Seamless Tube |
Hot-finished or Cold-worked |
| Condition |
Solution Annealed (mandatory) |
Critical for grain size control |
| Max Service Temperature |
~900°C (1650°F) for N08810/N08811 |
For creep service; ~540°C for corrosion |
| Grain Size Req. (N08810/N08811/N08120) |
ASTM No. 5 or coarser (per E 112) |
Mandatory for creep-rupture service |
2. Grades Covered by ASTM B407
| Grade |
UNS No. |
Common Name |
Grain Size Req. |
Primary Application |
| Grade A |
N08800 |
Incoloy 800 |
None specified |
General corrosion & high-temp oxidation |
| Grade B |
N08810 |
Incoloy 800H |
ASTM No. 5 or coarser |
Creep-rupture above 1100°F |
| Grade C |
N08811 |
Incoloy 800HT |
ASTM No. 5 or coarser |
Max creep life; γ′ strengthened |
| Grade D |
N08120 |
HR-120 |
ASTM No. 5 or coarser |
Higher strength; up to 1100°C |
3. Chemical Composition — ASTM B407 Table 1
Values are maximum unless shown as a range. Heat analysis per ASTM B407-22.
| Element |
N08800 (%) |
N08810 (%) |
N08811 (%) |
N08120 (%) |
Key Role |
| Carbon (C) |
0.10 max |
0.05–0.10 |
0.06–0.10 |
0.05–0.10 |
Controlled for creep; too high → brittleness |
| Manganese (Mn) |
1.50 max |
1.50 max |
1.50 max |
1.00 max |
Deoxidizer |
| Phosphorus (P) |
0.045 max |
0.045 max |
0.045 max |
0.045 max |
Impurity |
| Sulfur (S) |
0.015 max |
0.015 max |
0.015 max |
0.015 max |
Impurity (keep low) |
| Silicon (Si) |
1.00 max |
1.00 max |
1.00 max |
1.00 max |
Deoxidizer |
| Nickel (Ni) |
30.0–35.0 |
30.0–35.0 |
30.0–35.0 |
35.0–39.0 |
Austenite stabilizer; oxidation resistance |
| Chromium (Cr) |
19.0–23.0 |
19.0–23.0 |
19.0–23.0 |
23.0–27.0 |
Oxidation and carburization resistance |
| Copper (Cu) |
0.75 max |
0.75 max |
0.75 max |
0.50 max |
Residual |
| Titanium (Ti) |
0.15–0.60 |
0.15–0.60 |
0.15–0.60 |
— |
Stabilizer (N08800/10/11); γ′ former |
| Aluminum (Al) |
0.15–0.60 |
0.15–0.60 |
0.15–0.60 |
0.10–0.30 |
Al+Ti 0.85–1.20% for N08811 |
| Cobalt (Co) |
— |
— |
— |
3.0 |
Solid solution strengthener (HR-120) |
| Niobium (Nb) |
— |
— |
— |
0.10–0.50 |
Carbonitride former (HR-120) |
| Nitrogen (N) |
— |
— |
— |
0.20 |
Austenite stabilizer (HR-120) |
| Iron (Fe) |
min 39.5 |
min 39.5 |
min 39.5 |
Balance |
Balance; reduces cost vs pure nickel alloys |
Note: Iron is determined arithmetically by difference for N08800, N08810, N08811. N08120 has a specified iron balance. Al+Ti total must be 0.85–1.20% for N08811 per ASTM B407-22.
4. Mechanical Property Requirements — ASTM B407 Table 2
All values are minimum requirements per ASTM B407-22. Testing per ASTM E 8. Elongation measured over 2 in. (50 mm) or 4D gauge length.
| Grade / Condition |
Tensile Strength
min MPa (ksi) |
Yield Strength
min MPa (ksi) |
Elongation
min % |
Grain Size |
| N08800 — Cold-worked Annealed |
520 (75) |
205 (30) |
30 |
Not specified |
| N08800 — Hot-finished Annealed |
450 (65) |
170 (25) |
30 |
Not specified |
| N08810 — HF or CW Annealed |
450 (65) |
170 (25) |
30 |
ASTM No. 5 or coarser |
| N08811 — HF or CW Annealed |
450 (65) |
170 (25) |
30 |
ASTM No. 5 or coarser |
| N08120 — HF or CW Annealed |
655 (95) |
275 (40) |
30 |
ASTM No. 5 or coarser |
Grade Selection: For general high-temperature oxidation and corrosion service, specify N08800 (Incoloy 800). For creep-rupture critical service above 1100°F (593°C), specify N08810 (800H) with ASTM No. 5 grain. For maximum creep life and long-term thermal stability, specify N08811 (800HT) with Al+Ti 0.85–1.20%. For highest strength up to 1100°C, specify N08120 (HR-120) with TS≥655 MPa.
5. Heat Treatment & Grain Size Requirements
| Alloy |
Min Annealing Temp |
Grain Size Req. |
Purpose |
| N08800 (Incoloy 800) |
Not specified |
None |
General corrosion resistance |
| N08810 (Incoloy 800H) |
2050°F (1121°C) min |
ASTM No. 5 or coarser |
Creep-rupture above 1100°F |
| N08811 (Incoloy 800HT) |
2100°F (1149°C) min |
ASTM No. 5 or coarser |
Maximum creep life; γ′ strengthened |
| N08120 (HR-120) |
2150°F (1177°C) min |
ASTM No. 5 or coarser |
Highest creep strength; up to 1100°C |
Grain size verification per ASTM E 112 (planimetric, comparison, or intercept method). One test per lot.
Grain Size is Critical: The coarse grain size (ASTM No. 5 or coarser) is achieved by annealing at the minimum specified temperatures. This coarse grain structure is the key differentiator between N08810/N08811 and standard N08800 — it provides superior creep resistance by minimizing grain boundary sliding at elevated temperatures. Grain size must be certified on the MTC.
6. Testing & Inspection Requirements
| Test |
Requirement |
Reference Standard |
| Chemical Analysis |
One per heat; all elements per Table 1 |
ASTM B407 Table 1 / ASTM E 1473 |
| Tensile Test |
One per lot; full tubular or longitudinal strip specimen |
ASTM E 8 |
| Grain Size Test |
Mandatory for N08120, N08810, N08811 — ASTM No. 5 or coarser |
ASTM E 112 |
| Hydrostatic Test |
Standard leak test per agreed pressure; alternative to eddy current |
ASTM B407 |
| Eddy Current Test |
Alternative to hydrostatic; standard NDE for imperfections |
ASTM B407 |
| Product Analysis |
If requested by purchaser; check analysis tolerances per B829 |
ASTM B829 |
7. Pipe & Tube Dimensions — ASTM B407 Tolerances (per ASTM B829)
Dimensions follow ASME B36.19M for schedule dimensions. Tolerances per ASTM B829 for cold-drawn tube and hot-finished pipe.
| NPS |
OD (in) |
OD (mm) |
Sch 10S
(mm) |
Sch 40S
(mm) |
Sch 80S
(mm) |
CW Tube 0.035"
(mm) |
| 1/2 |
0.840 |
21.34 |
2.11 |
2.77 |
3.73 |
0.89 |
| 3/4 |
1.050 |
26.67 |
2.11 |
2.87 |
3.91 |
0.89 |
| 1 |
1.315 |
33.40 |
2.77 |
3.38 |
4.55 |
0.89 |
| 1-1/2 |
1.900 |
48.26 |
2.77 |
3.68 |
5.08 |
0.89 |
| 2 |
2.375 |
60.33 |
2.77 |
3.91 |
5.54 |
0.89 |
| 3 |
3.500 |
88.90 |
3.05 |
5.49 |
7.62 |
— |
| 4 |
4.500 |
114.30 |
3.05 |
6.02 |
8.56 |
— |
| 6 |
6.625 |
168.28 |
3.40 |
7.11 |
10.97 |
— |
Note: Cold-drawn tube tolerances: OD ±0.13 mm (D<12.7mm); ±0.25 mm (D 38-50.8mm); ±0.38 mm (D 50-76mm). Wall: average ±10–12.5%. Hot-finished pipe tolerances: OD ±0.38–0.79 mm per OD range; wall nominal ±12.5%. Dimensions per ASME B36.19M (Stainless Steel Pipe).
8. Industries & Applications
| Application |
Recommended Grade |
Temperature / Conditions |
| Ethylene Cracking Furnaces |
N08811 (800HT) |
Radiant tubes, inlet/outlet piping; 900–1050°C |
| Steam Methane Reformers |
N08810/N08811 |
Catalyst tubes, outlet piping; 750–900°C |
| Steam Superheater Tubes |
N08800 (800) |
High-pressure steam; 450–600°C |
| Pyroprocessing Equipment |
N08800/N08810 |
Kilns, calciners, furnace components |
| Heat Exchangers (High-Temp) |
N08800 (800) |
Shell-and-tube exchangers; 400–700°C shell side |
| Power Generation |
N08800 (800) |
Boiler components, superheater pendants; up to 560°C |
9. ASTM B407 vs B423 vs B729 — Nickel Alloy Pipe Comparison
| Property |
B407 (Incoloy 800 family) |
B423 (Incoloy 825) |
B729 (Alloy 20 / N08020) |
| Nickel (Ni) |
30–39% |
38–46% |
32–38% |
| Molybdenum (Mo) |
None |
2.5–4.0% |
2.0–3.0% |
| Copper (Cu) |
0.75 max |
1.5–3.0% |
3.0–4.0% |
| Max Temp (Creep) |
~900°C |
~540°C |
~540°C |
| Min. TS (HF Annealed) |
450 MPa |
517 MPa |
550 MPa |
| Primary Advantage |
High-temp oxidation |
Acid corrosion resistance |
Mixed acid (Alloy 20) |
| PREN (approx.) |
~22 |
~30 |
~34 |
10. Related Standards
| Standard |
Scope |
Relationship to B407 |
| ASTM B829 |
General Requirements for Nickel and Nickel Alloy Pipe and Tube |
Mandatory supplementary requirements |
| ASTM B423 |
Nickel-Iron-Chromium-Molybdenum-Copper Seamless Pipe (Incoloy 825) |
Acid/corrosion service alternative; no high-temp creep capability |
| ASTM B729 |
Seamless UNS N08020, N08026 Pipe (Alloy 20 family) |
Different alloy; mixed acid, nitric + sulfuric |
| ASME SB407 |
ASME Section II Part B — Incoloy 800 adoption |
ASME Code compliance; identical requirements |
| ASTM B168 |
Nickel-Chromium-Iron (Inconel 600) Plate, Sheet, Strip |
Matching plate for fabrication of B407 pipe fittings |
| AWS A5.14 |
Nickel Filler Metal (ERNiCr-3, ERNiCrCoMo-1) |
Filler wire for welding B407 pipe |
| ASTM E 112 |
Determining Grain Size |
Mandatory grain size verification for N08810/N08811/N08120 |
| ASME B31.3 |
Process Piping Code |
Governs allowable stress for B407 pipe in process plants |
11. How to Order — Required Information
| No. |
Item |
Requirement / Example |
| 1 |
Specification |
ASTM B407 / ASME SB407 |
| 2 |
Grade / UNS |
N08800 (Incoloy 800), N08810 (800H), N08811 (800HT), or N08120 (HR-120) |
| 3 |
Manufacturing Condition |
Hot-finished Annealed or Cold-worked Annealed |
| 4 |
NPS & Schedule / Wall Thickness |
e.g., NPS 4 Sch 40S or NPS 6 × 7.11 mm WT |
| 5 |
Length |
Single Random (~6 m), Double Random (~12 m), or Cut-to-length |
| 6 |
End Preparation |
Plain End (PE), Beveled End (BE per ASME B16.25) |
| 7 |
Grain Size Certificate |
Mandatory for N08810, N08811, N08120 — ASTM No. 5 or coarser per ASTM E 112 |
| 8 |
Supplementary Tests |
Hydrostatic test, PMI verification, product analysis |
| 9 |
Certification |
EN 10204 3.1 Certified Mill Test Report (CMTR) with grain size report |
Download ASTM B407 / ASME SB407 Standard (PDF)
The official ASTM B407-22 PDF is available from our HT Pipe Download Center. The document includes full chemical composition Table 1, mechanical property requirements, grain size specifications, dimensional tolerances, and ordering guidance.
Go to Download Center | Request MTC / Quotation
12. Frequently Asked Questions
Q: What is the maximum service temperature for Incoloy 800 vs Incoloy 800H vs Incoloy 800HT?
Incoloy 800 (N08800): approximately 540°C (1000°F) for continuous corrosion service, and up to 900°C for intermittent oxidation. Incoloy 800H (N08810): up to 900°C (1650°F) with superior creep-rupture strength above 593°C (1100°F) due to the minimum 2050°F annealing temperature and ASTM No. 5 grain. Incoloy 800HT (N08811): up to 900°C (1650°F) with the highest creep rupture life due to Al+Ti 0.85–1.20% providing gamma-prime (γ′) precipitation strengthening, with minimum annealing temperature of 2100°F (1149°C).
Q: Why is grain size important for N08810 and N08811?
Grain size ASTM No. 5 or coarser (per ASTM E 112) is the key differentiator that enables N08810 and N08811 to achieve the creep-rupture properties required for high-temperature service. Coarse grains reduce grain boundary area, which is the primary path for creep deformation at elevated temperatures. The grain size is controlled by the minimum annealing temperature (2050°F for N08810, 2100°F for N08811) — this must be certified on the MTC. Fine-grained material may not meet creep requirements in service.
Q: What is the difference between ASTM B407 and ASME SB407?
Technically identical in chemistry and mechanical property requirements. ASME SB407 is ASTM B407 adopted into ASME Section II Part B for Boiler and Pressure Vessel Code compliance. For ASME code-stamped pressure systems (BPVC, B31.1, B31.3), specify ASME SB407 to ensure Code compliance. Most mills supply dual-certified B407/SB407 pipe at no additional cost. Specify SB407 when purchasing for ASME-certified projects.
Q: Is post-weld heat treatment required for ASTM B407 pipe?
PWHT is generally not required for Incoloy 800/800H/800HT alloys. These alloys do not require PWHT to restore corrosion resistance because they are not susceptible to sensitization (chromium carbide precipitation) in the same way as austenitic stainless steels. Welding with ERNiCr-3 (Inconel 82) or ERNiCrCoMo-1 (Inconel 617) filler is recommended. Interpass temperature should be kept below 150°C (300°F). For very thick sections or severe service, solution annealing after welding may be specified.
Q: When should I specify UNS N08120 (HR-120) instead of Incoloy 800?
Specify UNS N08120 (HR-120) when the application requires the highest creep strength in the Incoloy family. Key advantages: minimum tensile strength of 655 MPa (vs 450 MPa for N08800) — approximately 45% stronger; higher chromium (23–27% vs 19–23%) for superior oxidation and nitridation resistance; service temperature up to 1100°C (vs 900°C for 800H/HT). HR-120 is preferred for reformer outlet components, advanced cracking furnaces, and applications where space or weight constraints require higher strength-to-weight ratios.
Request a Quote — ASTM B407 Incoloy 800 / 800H / 800HT Seamless Pipe
Zhengzhou Huitong (HT Pipe) supplies ASTM B407 / ASME SB407 seamless pipe in all specified grades (N08800, N08810, N08811, N08120) with EN 10204 3.1 CMTRs, grain size certifications, and competitive lead times for ethylene crackers, reformers, and high-temperature process applications.
