ASTM B408/B408M is the standard specification by ASTM International covering nickel-iron-chromium alloys in the form of hot-worked and cold-worked rod, bar, and shapes. The most widely used grades are UNS N08800 (Alloy 800 / Incoloy 800), UNS N08810 (Alloy 800H), and UNS N08811 (Alloy 800HT). The companion specification ASME SB-408 adopts identical requirements for ASME BPVC compliance.
Zhengzhou Huitong (HT Pipe) supplies ASTM B408 / SB-408 compliant nickel-iron-chromium alloy rods and bars with full Mill Test Certificates (MTC) per EN 10204 3.1.
1. Standard Scope & Designation
ASTM B408 covers the following nickel-iron-chromium grades:
| UNS No. |
Common Name |
Alloy Type |
Key Features & Application |
| UNS N08800 |
Alloy 800 / Incoloy 800 |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al+Ti-0.15-0.60% |
General high-temp — furnaces, heat exchangers, petrochemical |
| UNS N08810 |
Alloy 800H |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al+Ti-0.15-0.60%, C-0.05-0.10% |
High-temperature creep — 538°C+ service |
| UNS N08811 |
Alloy 800HT |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al 0.15-0.60%, Ti 0.15-0.60%, C-0.06-0.10% |
Creep rupture — 593°C+ service, controlled grain size |
| UNS N08120 |
Alloy 801 / DS |
Ni-30-35%, Cr-19-23%, C-0.05-0.10% |
Carburizing resistance — furnace components |
| UNS N08890 |
Alloy 890 |
Ni-30% min, Cr-19-23%, Cu-0.50-1.50% |
Improved resistance to reducing acids |
Scope Statement: "This specification covers nickel-iron-chromium alloys (UNS N08120, N08800, N08810, N08811, and N08890) in the form of hot-worked and cold-worked rounds, squares, hexagons, and rectangles for high-temperature and corrosive service."
| Designation |
Issuing Body |
Unit System |
Latest Edition |
| ASTM B408 |
ASTM International |
Inch-Pound |
B408/B408M-21 |
| ASTM B408M |
ASTM International |
SI (Metric) |
B408/B408M-21 |
| ASME SB-408 |
ASME (BPVC Sec. II Part B) |
Both |
2025 Edition |
2. Alloy Grades Covered by ASTM B408
ASTM B408 covers five nickel-iron-chromium alloys designed for high-temperature and corrosive environments:
| UNS No. |
Commercial Designation |
Alloy Type |
Key Features & Typical Application |
| UNS N08800 |
Alloy 800 / Incoloy 800 |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al+Ti-0.15-0.60% |
General high-temp — furnaces, heat exchangers, petrochemical |
| UNS N08810 |
Alloy 800H |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al+Ti-0.15-0.60%, C-0.05-0.10% |
High-temperature creep — 538°C+ service |
| UNS N08811 |
Alloy 800HT |
Ni-30-35%, Fe-39.5% min, Cr-19-23%, Al 0.15-0.60%, Ti 0.15-0.60%, C-0.06-0.10% |
Creep rupture — 593°C+ service, controlled grain size |
| UNS N08120 |
Alloy 801 / DS |
Ni-30-35%, Cr-19-23%, C-0.05-0.10% |
Carburizing resistance — furnace components |
| UNS N08890 |
Alloy 890 |
Ni-30% min, Cr-19-23%, Cu-0.50-1.50% |
Improved resistance to reducing acids |
3. Chemical Composition — Key Grades (ASTM B408)
Values are maximum unless shown as a range. Heat analysis per ASTM B408.
| Grade |
Ni% |
Cr% |
Fe% |
C% |
Al% |
Ti% |
Cu% |
Mn% |
| N08800 |
30.0–35.0 |
19.0–23.0 |
39.5 min |
0.10 |
0.15–0.60 |
0.15–0.60 |
0.75 |
1.50 |
| N08810 |
30.0–35.0 |
19.0–23.0 |
39.5 min |
0.05–0.10 |
0.15–0.60 |
0.15–0.60 |
0.75 |
1.50 |
| N08811 |
30.0–35.0 |
19.0–23.0 |
39.5 min |
0.06–0.10 |
0.15–0.60 |
0.15–0.60 |
0.75 |
1.50 |
| N08120 |
30.0–35.0 |
19.0–23.0 |
39.5 min |
0.05–0.10 |
0.15–0.60 |
0.15–0.60 |
0.75 |
1.50 |
Note: Product analysis tolerances per ASTM B408 apply.
4. Mechanical Property Requirements (ASTM B408)
All values are minimum requirements unless otherwise stated. Tensile testing per ASTM E8.
| Grade |
UNS |
Tensile Strength
min MPa (ksi) |
Yield Strength 0.2%
min MPa (ksi) |
Elong.
min % |
Hardness
max |
| Alloy 800 |
N08800 |
517 (75) |
207 (30) |
30 |
192 HB |
Annealed |
| Alloy 800H |
N08810 |
450 (65) |
170 (25) |
30 |
192 HB |
Solution Annealed |
| Alloy 800HT |
N08811 |
450 (65) |
170 (25) |
30 |
192 HB |
Solution Annealed |
Note: Hardness testing per ASTM E10 (Brinell) or ASTM E18 (Rockwell). Cold-worked bar may exhibit higher strength due to cold work.
5. Heat Treatment Requirements
| Grade |
Condition |
Heat Treatment |
Cooling |
| UNS N08800 (Alloy 800) |
Annealed |
982–1066°C (1800–1950°F) |
Water quench or rapid air cool |
| UNS N08810 (Alloy 800H) |
Solution Annealed |
1093–1204°C (2000–2200°F) |
Water quench |
| UNS N08811 (Alloy 800HT) |
Solution Annealed |
1093–1204°C (2000–2200°F) |
Water quench |
| UNS N08120 |
Solution Annealed |
1093–1204°C (2000–2200°F) |
Water quench |
Important: Alloy 800H and 800HT require solution annealing at higher temperatures (2000–2200°F) than standard Alloy 800 to ensure proper grain coarsening for creep resistance. Alloy 800HT also requires Al+Ti content of 0.85–1.20% to form gamma prime precipitates that provide additional creep strength at temperatures above 1100°F (593°C).
6. Testing & Inspection Requirements
| Test |
Requirement |
Reference Standard |
| Chemical Analysis (Heat) |
One per heat / melt; all elements per Table 1 |
ASTM E1473 / E354 |
| Tensile Test |
One per lot (same heat, same condition, same diameter group) |
ASTM E8 / E8M |
| Hardness Test |
Brinell or Rockwell; one per lot |
ASTM E10 / E18 |
| Grain Size |
Required for 800H and 800HT; ASTM E112 Method |
ASTM E112 |
| Visual & Dimensional |
Surface condition, straightness, diameter tolerance |
ASTM B408 Tables |
| PMI (Positive Material ID) |
When specified by purchaser |
ASTM E1473 |
7. Rod & Bar Dimensions — Available Sizes
ASTM B408 covers various rod and bar forms. Common commercial size ranges:
| Form |
Diameter / Width |
Typical Length |
Tolerance |
| Hot-Worked Round |
12.7 – 200 mm (1/2–8 in.) |
3.0 – 6.0 m random |
±0.13 mm typical |
| Cold-Worked Round |
6.35 – 100 mm (1/4–4 in.) |
3.0 – 6.0 m random |
±0.05 mm typical |
| Hot-Worked Square |
12.7 – 150 mm |
3.0 – 6.0 m random |
±0.25 mm typical |
| Hot-Worked Hexagon |
12.7 – 100 mm (AF) |
3.0 – 6.0 m random |
±0.25 mm typical |
Note: Diameter tolerances per ASTM B408 tables. Cut-to-length available on request.
8. Industries & Applications
| Industry |
Recommended Grades |
Typical Applications |
| Petrochemical |
N08800, N08810, N08811 |
Catalytic cracker tubing, reformer outlet manifolds, ethylene furnace components |
| Heat Treatment |
N08800, N08810 |
Furnace baskets, radiant tubes, retorts, conveyor belts |
| Power Generation |
N08800, N08810, N08811 |
Superheater tubes, boiler components, steam piping |
| Chemical Processing |
N08800, N08890 |
Nitric acid condensers, hydrogenation reactors, acid production equipment |
| Nuclear Industry |
N08800 |
Steam generator tubing, reactor internals, high-temp structural components |
| Industrial Furnaces |
N08810, N08811, N08120 |
Carburizing furnace parts, radiant tubes, burner nozzles |
9. B408 vs B409 vs B407 — Ni-Fe-Cr Alloy Specifications Compared
| Criteria |
ASTM B408 |
ASTM B409 |
ASTM B407 |
| Product Form |
Rod, Bar, Shapes |
Plate, Sheet, Strip |
Seamless Pipe & Tube |
| Processing |
Hot-worked, Cold-worked |
Hot-rolled, Cold-rolled |
Hot-finished, Cold-drawn |
| Key Grades |
N08800, N08810, N08811, N08120 |
N08800, N08810, N08811 |
N08800, N08810, N08811 |
| Mechanical Props |
TS≥517 MPa (N08800) |
TS≥517 MPa (N08800) |
TS≥517 MPa (N08800) |
| Max Service Temp |
N08811: 982°C |
N08811: 982°C |
N08811: 982°C |
| Primary Use |
Machined parts, shafts, fasteners |
Pressure vessels, heat exchangers |
Process piping, furnace tubing |
Key Distinction: ASTM B408, B409, and B407 form a complementary family of specifications for Alloy 800-type materials across all product forms. B408 covers rod/bar (solid long products), B409 covers flat products (plate, sheet, strip), and B407 covers tubular products (seamless pipe and tube). All share the same UNS grades and similar chemical/mechanical requirements.
10. Related Standards
| Standard |
Scope |
Relationship |
| ASTM B409 |
Ni-Fe-Cr Alloy Plate, Sheet, Strip |
Flat product companion specification |
| ASTM B407 |
Ni-Fe-Cr Alloy Seamless Pipe & Tube |
Tubular product companion specification |
| ASTM B880 |
General Requirements for Nickel Alloys |
Governs tolerances, testing, certification |
| ASTM E8 / E8M |
Tension Testing of Metallic Materials |
Tensile test method required by B408 |
| ASTM E112 |
Grain Size Measurement |
Required for 800H and 800HT |
| ASTM E1473 |
Chemical Analysis of Ni & Ni Alloys |
Chemical analysis method |
| ASME SB-408 |
BPVC Section II Part B |
ASME adoption with CMTR |
| DIN EN 10204 |
Metallic Products — Inspection Documents |
3.1 CMTR certification |
11. How to Order — Required Information
| No. |
Item |
Requirement / Example |
| 1 |
Specification |
ASTM B408 / ASME SB408 |
| 2 |
Grade / UNS |
e.g., UNS N08800 (Alloy 800) or UNS N08811 (Alloy 800HT) |
| 3 |
Shape |
Round, Square, Hexagon, Rectangle |
| 4 |
Processing |
Hot-worked (HW) or Cold-worked (CW) |
| 5 |
Diameter / Size |
e.g., 50 mm round |
| 6 |
Length |
Random (RL ~3–6 m) or Cut-to-length |
| 7 |
Condition |
Annealed (default) or Solution Annealed (800H/800HT) |
| 8 |
Supplementary Tests |
PMI, intergranular corrosion, UT, impact testing |
| 9 |
Certification |
EN 10204 3.1 Certified Mill Test Report |
| 10 |
Quantity |
Pieces or total weight (kg / metric tons) |
Download ASTM B408/B408M Standard (PDF)
The official ASTM B408/B408M-21 PDF is available from our HT Pipe Download Center. The document includes full chemical composition, mechanical property requirements, heat treatment, dimensions and tolerances, testing methods, and supplementary requirements.
Go to Download Center | Request MTC / Quotation
12. Frequently Asked Questions
Q: What is ASTM B408 nickel-iron-chromium alloy rod?
ASTM B408/B408M is the standard specification for nickel-iron-chromium alloys in the form of hot-worked and cold-worked rod, bar, and shapes. It covers UNS N08800 (Alloy 800/Incoloy 800), UNS N08810 (Alloy 800H), UNS N08811 (Alloy 800HT), UNS N08120, and UNS N08890. These alloys are designed for high-temperature structural and corrosive service.
Q: What is Alloy 800 (UNS N08800 / Incoloy 800)?
Alloy 800 (UNS N08800) is a nickel-iron-chromium alloy with excellent resistance to oxidation and carburization at high temperatures. It maintains a stable austenitic structure and is limited to 427°C for ASME Section VIII pressure vessels due to its carbon content. Higher-temperature applications require Alloy 800H or 800HT.
Q: What is the difference between Alloy 800, 800H, and 800HT?
Alloy 800 (N08800) has C≤0.10% and is used up to 427°C for ASME pressure vessels. Alloy 800H (N08810) has C 0.05–0.10% and is solution-annealed at higher temperature for coarser grains and creep resistance up to 982°C. Alloy 800HT (N08811) adds tighter Al+Ti control (0.85–1.20%) for gamma-prime precipitation hardening, providing the highest creep strength.
Q: What are the mechanical properties of Alloy 800 rod per ASTM B408?
In the annealed condition, UNS N08800 (Alloy 800) rod and bar must meet: minimum tensile strength 517 MPa (75 ksi), minimum yield strength 207 MPa (30 ksi), and minimum elongation 30%. Hardness maximum is 192 HB.
Q: What is the difference between ASTM B408 and ASTM B407?
ASTM B408 covers nickel-iron-chromium alloy rod, bar, and shapes. ASTM B407 covers the same alloy family in seamless pipe and tube form. Both share the same UNS grades (N08800, N08810, N08811) and similar chemical and mechanical requirements.
Q: Is ASTM B408 the same as ASME SB-408?
Technically identical in chemistry and mechanical properties. ASME SB-408 is ASTM B408 adopted into ASME BPVC Section II Part B. SB-408 additionally requires Certified Material Test Reports (CMTR) with full traceability for ASME Code-stamped equipment. Most mills supply dual-certified B408/SB-408 material.
Request a Quote — ASTM B408 Ni-Fe-Cr Alloy Rod & Bar
Zhengzhou Huitong (HT Pipe) supplies ASTM B408 / SB-408 compliant nickel-iron-chromium alloy rods and bars in UNS N08800 (Alloy 800), N08810 (800H), N08811 (800HT), and other grades. Full EN 10204 3.1 CMTRs and competitive lead times from affiliated mills.
