Incoloy 800 / 800H / 800HT PlateASTM B409 UNS N08800 · Manufacturer, trader & exporter, India
Also sold as Alloy 800 · UNS N08800 / N08810 / N08811 · W.Nr 1.4876 · Incoloy 800H
Incoloy 800 / 800H / 800HT plate is Alloy 800 (UNS N08800) rolled to 3/16" (4.76 mm) thickness and above for pressure parts, heavy sections and cut blanks under ASTM B409. It is a nickel–iron–chromium alloy for high-temperature service, chosen for furnaces, petrochemical heaters and high-temperature piping. Kanak Steel & Engineering Co. manufactures, trades and exports it from Mumbai; EN 10204 3.1 or 3.2 certificates are available on request / as specified in the PO. Markets we have supplied to include Oman, UAE, Saudi Arabia, Brazil, Argentina, Spain and Chile (India is the home market).
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Incoloy 800 / 800H / 800HT Plate?
Incoloy 800 / 800H / 800HT plate is a nickel–iron–chromium alloy for high-temperature service supplied as plate to ASTM B409 (UNS N08800). Buyers specify it for furnaces, petrochemical heaters and high-temperature piping. It is also sold as Alloy 800, UNS N08800 / N08810 / N08811, W.Nr 1.4876.
- What it is
- Nickel–iron–chromium alloy for high-temperature service
- Standard
- ASTM B409
- Thickness
- 3/16" (4.76 mm) and above
- Density
- 7.94 g/cm³
- Supplied as
- Annealed · HRAP · cut to size
- Best at
- Furnaces, petrochemical heaters and high-temperature piping
Incoloy 800 / 800H / 800HT Plate Specification & Sizes
| Material standard | ASTM B409 · ASME SB-409 |
|---|---|
| General requirements | ASTM B906 — dimensions, tolerances and finishes |
| Grade | Incoloy 800 / 800H / 800HT · UNS N08800 · N08810 (800H) · N08811 (800HT) · W.Nr 1.4876 · 1.4958 · 1.4959 |
| Thickness | 3/16" (4.76 mm) and above — thinner is sheet |
| Width × length | 1000 / 1250 / 1500 / 2000 / 2500 mm × up to 6000 mm, or cut to drawing |
| Condition & finish | Annealed · hot rolled, annealed & pickled (No.1) |
| Cutting | Cut to size — rectangles, strips, circles & rings |
| Testing | PMI · UT (plate) · intergranular corrosion · hardness, on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection · packing list · certificate of origin |
Sheet or plate?
Both are ordered under ASTM B409, so buyers often mix them up. The line is thickness: below 3/16" is sheet, 3/16" and over is plate. If your drawing calls for under 3/16" (4.76 mm), you need Incoloy 800 / 800H / 800HT sheet; for 4.76 mm and up, you are in the right place.
Incoloy 800 / 800H / 800HT Plate Cut to Size
Most 800 plate leaves us as pieces, not full mill plates. Cutting from a full plate means you pay only for what you use, and each piece keeps the heat number of the plate it came from.
| Full & part plates | Full mill plates, halves and quarters |
|---|---|
| Rectangles & strips | To your list of finished sizes, or to a drawing |
| Circles & rings | Blanks for blind flanges, covers, tube sheets and nozzles |
| Machining allowance | State finished size and allowance; thermally cut edges are normally machined back |
| Traceability | Heat number transferred to every piece before cutting |
Send a cutting list or DXF; we nest pieces to reduce off-cut and quote per piece.
Incoloy 800 / 800H / 800HT Plate Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Chromium | As specified |
| Iron | As specified |
| Carbon | As specified |
| Aluminium | As specified |
| Titanium | As specified |
| Copper | As specified |
| Manganese | As specified |
| Silicon | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B409 for UNS N08800 / N08810.
Incoloy 800 / 800H / 800HT Plate Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM B409 for UNS N08800 / N08810 — Annealed plate.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.94 g/cm³ |
| Melting range | 1357 – 1385 °C |
| Magnetic | Non-magnetic |
Incoloy 800 / 800H / 800HT Equivalent Grades
Incoloy 800 / 800H / 800HT Plate Weight Chart & Calculator
Use this to budget freight and price per piece. Weight (kg) = length (m) × width (m) × thickness (mm) × 7.94.
Example: 2000 × 1000 × 10 mm
2.0 × 1.0 × 10 × 7.94 = 158.8 kg
Total weight —
| Thickness | 2000 × 1000 plate | Per m² |
|---|---|---|
| 5 mm | 79.4 kg | 39.7 kg |
| 6 mm | 95.3 kg | 47.6 kg |
| 8 mm | 127.0 kg | 63.5 kg |
| 10 mm | 158.8 kg | 79.4 kg |
| 12 mm | 190.6 kg | 95.3 kg |
| 16 mm | 254.1 kg | 127.0 kg |
| 20 mm | 317.6 kg | 158.8 kg |
| 25 mm | 397.0 kg | 198.5 kg |
Six-digit Harmonized System heading (iron and steel, chapter 72–73). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Incoloy 800 / 800H / 800HT Plate with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. Incoloy 800 / 800H / 800HT is most often mixed up with Inconel 825 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen; those come from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Incoloy 800 / 800H / 800HT | Inconel 825 |
|---|---|---|
| Nickel | As specified | As specified |
| Chromium | As specified | As specified |
| Molybdenum | — | As specified |
| Copper | As specified | As specified |
| Titanium | As specified | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Incoloy 800 / 800H / 800HT Plate Price — What Decides It
Two quotes for "800 plate" can differ by 20% and both be fair. We quote 800 plate per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
Incoloy 800 / 800H / 800HT Plate Testing & Inspection
Plate goes into pressure parts and heavy sections, so it is inspected for internal soundness and flatness as well as chemistry. These tests are added to the order and reported on the certificate or as separate reports.
| Ultrasonic testing | Straight-beam UT to ASTM A578 (levels A, B or C; plate 10 mm and over, applied to nickel alloys by agreement) or EN 10160 (S0–S3 body, E0–E4 edge classes) |
|---|---|
| Flatness & dimensions | Per ASTM B906 tables for thickness, width and length |
| Corrosion testing | As your specification requires — commonly ASTM G28, Method A (e.g. 625) or Method B (e.g. C276, C22) |
| PMI | Alloy verification on each plate, or each cut piece if required |
| Third-party inspection | Witness by your inspector or agency, with an EN 10204 3.2 certificate |
UT checks the plate body along a scan grid and a band along each edge, where laminations matter most for welding.
Incoloy 800 / 800H / 800HT Plate Applications
Plate is chosen for pressure-bearing walls, heavy sections and parts machined from solid. For linings, bellows and pressed parts, see Incoloy 800 / 800H / 800HT sheet.
Incoloy 800 / 800H / 800HT Plate vs 310S, 600 and 825
| Grade | Plate standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Inconel 600 | ASTM B168 | — | High-temperature oxidation, caustic and nuclear service |
| Incoloy 800 / 800H / 800HT | ASTM B409 | — | Furnaces, petrochemical heaters and high-temperature piping |
| SS 310 / 310S | ASTM A240 | ≈ 25 | Furnaces, burners and heat treatment at high temperature |
| Inconel 825 | ASTM B424 | ≈ 31 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Incoloy 800 / 800H / 800HT Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether 800 fits.
Balanced nickel and chromium resist oxidation and carburisation in furnace atmospheres.
Controlled carbon and coarse grain give 800H/HT their creep-rupture strength above 600 °C.
Aluminium and titanium improve high-temperature strength.
For aqueous acid service choose 825 instead.
How your 800 plate order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI can be arranged depending on product and requirements, as specified in the PO.
- 03Processing — cutting to your sizes, with heat numbers transferred where the PO requires it.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Fabricating Heavy Incoloy 800 / 800H / 800HT Plate
Shells, heads and tube sheets mean thick sections and multi-pass welds. These are the points that decide whether 800 plate keeps its corrosion resistance after fabrication; matching filler is ERNiCr-3 (AWS A5.14).
General guidance only; follow your approved WPS, PQR and design code.
| Joint preparation | Bevel above about 2.4 mm, with a wider included angle (around 80°) and thinner land than for steel — nickel weld pools do not flow far. |
|---|---|
| Interpass temperature | Keep it low — typically 93 °C (200 °F) maximum for Ni-Cr-Mo alloys such as C276, C22 and 625; follow your WPS for other nickel alloys. No preheat on clean, dry plate. |
| Cleanliness | Remove grease, paint, marking crayon and sulphur-bearing compounds before welding or heat treatment. |
| Machining | Nickel alloys work-harden: carbide tools, positive rake, low speed and a feed heavy enough to cut under the hardened layer. |
How to Order Incoloy 800 / 800H / 800HT Plate: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Standard and edition — e.g. ASTM B409-latest
- Thickness × width × length, and number of pieces
- Full plates or cut pieces (attach drawing)
- Certificate type — 3.1 or 3.2, and the inspection agency
- Extra tests — UT, intergranular corrosion
- Delivery port, Incoterm and required date
Incoloy 800 / 800H / 800HT plate — questions buyers ask
Is Incoloy 800 / 800H / 800HT the same as Alloy 800?
Alloy 800, UNS N08800 / N08810 / N08811, W.Nr 1.4876 are names used for Incoloy 800 / 800H / 800HT (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order), and plate is ordered to ASTM B409 whichever name is on the enquiry.
What thickness counts as Incoloy 800 / 800H / 800HT plate?
Under ASTM B409 and its general-requirements standard, flat material below 3/16" (4.76 mm) is sheet (or strip if narrower than 24") and 3/16" (4.76 mm) and over is plate. Order the form that matches your drawing thickness.
What is the price of Incoloy 800 / 800H / 800HT plate per kg?
It moves with nickel on the LME, so a fixed list price is out of date within days. Thickness, cut size, quantity and documents also change it. Send your size and quantity and we quote the same working day.
Do you supply ultrasonically tested Incoloy 800 / 800H / 800HT plate?
Yes, UT can be added to the order — to ASTM A578 or the level your specification states. The UT report is supplied with the mill certificate.
Can Incoloy 800 / 800H / 800HT plate be cut into circles and rings?
Yes. Blanks for blind flanges, covers and tube sheets are cut from plate to your drawing, with the heat number marked on every piece.
What machining allowance should I leave on cut plate?
It depends on the cutting method and finished tolerance. Give us the finished size and your allowance; thermally cut edges are normally machined back to sound metal.
How heavy is a Incoloy 800 / 800H / 800HT plate?
Weight (kg) = length (m) × width (m) × thickness (mm) × 7.94. A 2000 × 1000 × 10 mm plate weighs about 159 kg; use the calculator on this page for your size.
What documents come with an export shipment?
An EN 10204 3.1 mill certificate (or 3.2 with a third-party inspector), commercial invoice, packing list with heat numbers, and certificate of origin. Test reports are added for any extra tests ordered.
Incoloy 800 / 800H / 800HT or Inconel 825 — which should I choose?
Incoloy 800 / 800H / 800HT is chosen for furnaces, petrochemical heaters and high-temperature piping. Inconel 825 is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026