Inconel 718 PlateASTM B670 UNS N07718 · Manufacturer, stockist & exporter, India
Also sold as Alloy 718 · UNS N07718 · W.Nr 2.4668 · Precipitation-hardening nickel alloy
Inconel 718 plate is Alloy 718 (UNS N07718) rolled to 3/16" (4.76 mm) thickness and above for pressure parts, heavy sections and cut blanks under ASTM B670. It is a age-hardenable nickel–chromium alloy with niobium and molybdenum, chosen for very high strength at temperatures up to about 650 °C. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Inconel 718 Plate?
Inconel 718 plate is an age-hardenable nickel–chromium alloy with niobium and molybdenum supplied as plate to ASTM B670 (UNS N07718). Buyers specify it for very high strength at temperatures up to about 650 °C. It is also sold as Alloy 718, UNS N07718, W.Nr 2.4668.
- What it is
- Age-hardenable nickel–chromium alloy with niobium and molybdenum
- Standard
- ASTM B670 · AMS 5596
- Thickness
- 3/16" (4.76 mm) and above
- Density
- 8.19 g/cm³
- Supplied as
- Annealed · HRAP · cut to size
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Plate Specification & Sizes
| Material standard | ASTM B670 · AMS 5596 · ASME SB-637 |
|---|---|
| General requirements | ASTM B906 — dimensions, tolerances and finishes |
| Grade | Inconel 718 · UNS N07718 · W.Nr 2.4668 |
| 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 B670, 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 Inconel 718 sheet; for 4.76 mm and up, you are in the right place.
Inconel 718 Plate Cut to Size
Most 718 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.
Inconel 718 Plate Chemical Composition
| Element | Weight % (producer reference) |
|---|---|
| Nickel (+Co) | 50.00 – 55.00 |
| Chromium | 17.00 – 21.00 |
| Iron | Balance |
| Niobium (+Ta) | 4.75 – 5.50 |
| Molybdenum | 2.80 – 3.30 |
| Titanium | 0.65 – 1.15 |
| Aluminium | 0.20 – 0.80 |
| Cobalt | 1.00 max |
| Carbon | 0.08 max |
| Manganese | 0.35 max |
| Silicon | 0.35 max |
| Phosphorus | 0.015 max |
| Sulphur | 0.015 max |
| Boron | 0.006 max |
| Copper | 0.30 max |
Inconel 718 Plate Mechanical Properties
| Specification | Product form | Condition | Requirement values |
|---|---|---|---|
| ASTM B670 (B670-25) | plate, sheet, strip | annealed (per current scope) | As specified |
Numerical requirements are not shown until the current edition of each standard has been verified. Mechanical properties depend on product form, size, condition and heat treatment — state them on the purchase order.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.19 g/cm³ |
| Melting range | 1260 – 1336 °C |
| Magnetic | Non-magnetic |
Typical / reference values (producer data, Special Metals SMC-045) — not specification requirements.
Inconel 718 Equivalent Grades
Values follow Special Metals INCONEL alloy 718 bulletin SMC-045 (2007) — producer reference composition, not a specification requirement; specification limits in ASTM B637-26, B670-25 and A1014/A1014M-26 are pending current standard text. Always check against the edition named on your purchase order.
Inconel 718 Plate Weight Chart & Calculator
Use this to budget freight and price per piece. Weight (kg) = length (m) × width (m) × thickness (mm) × 8.19.
Example: 2000 × 1000 × 10 mm
2.0 × 1.0 × 10 × 8.19 = 163.8 kg
Total weight —
| Thickness | 2000 × 1000 plate | Per m² |
|---|---|---|
| 5 mm | 81.9 kg | 40.9 kg |
| 6 mm | 98.3 kg | 49.1 kg |
| 8 mm | 131.0 kg | 65.5 kg |
| 10 mm | 163.8 kg | 81.9 kg |
| 12 mm | 196.6 kg | 98.3 kg |
| 16 mm | 262.1 kg | 131.0 kg |
| 20 mm | 327.6 kg | 163.8 kg |
| 25 mm | 409.5 kg | 204.8 kg |
Six-digit Harmonized System heading (nickel alloy, chapter 75). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Inconel 718 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. Inconel 718 is most often mixed up with Inconel 625 — 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 | Inconel 718 (producer reference) | Inconel 625 |
|---|---|---|
| Nickel | 50.00 – 55.00 | As specified |
| Chromium | 17.00 – 21.00 | As specified |
| Molybdenum | 2.80 – 3.30 | As specified |
| Copper | 0.30 max | — |
| Titanium | 0.65 – 1.15 | As specified |
| Niobium | 4.75 – 5.50 | As specified |
| Iron | Balance | As specified |
| Manganese | 0.35 max | As specified |
Inconel 718 Plate Price — What Decides It
Two quotes for "718 plate" can differ by 20% and both be fair. We quote 718 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.
Inconel 718 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.
Inconel 718 Plate Applications
Plate is chosen for pressure-bearing walls, heavy sections and parts machined from solid. For linings, bellows and pressed parts, see Inconel 718 sheet.
Inconel 718 Plate vs 625, 600 and 825
| Grade | Plate standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Inconel 600 | ASTM B168 | — | High-temperature oxidation, caustic and nuclear service |
| Inconel 718 | ASTM B670 · AMS 5596 | — | Very high strength at temperatures up to about 650 °C |
| Inconel 825 | ASTM B424 | ≈ 31 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| Inconel 625 | ASTM B443 | ≈ 51 | Seawater, high strength and high temperature in one alloy |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Inconel 718 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 718 fits.
Niobium forms the gamma-double-prime precipitate that gives 718 its high strength after age hardening.
Keeps very high strength and creep resistance up to about 650 °C.
Its slow ageing response gives good resistance to strain-age cracking during post-weld heat treatment; welding procedure and post-weld treatment still follow the applicable code and specification.
718 is chosen for strength; for corrosion alone, 625 or 825 are usually better value.
How your 718 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 before processing is available on request.
- 03Processing — cutting to your sizes, with heat numbers transferred to every piece.
- 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 Inconel 718 Plate
Shells, heads and tube sheets mean thick sections and multi-pass welds. These are the points that decide whether 718 plate keeps its corrosion resistance after fabrication; matching filler is ERNiFeCr-2 (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 Inconel 718 Plate: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Standard and edition — e.g. ASTM B670-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 — NACE, UT, intergranular corrosion
- Delivery port, Incoterm and required date
Inconel 718 plate for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiTechnical documentation
A Kanak Steel technical data sheet for this product is being prepared. It is released as a PDF only after the current standard text, each value and its evidence, and a named technical reviewer have been confirmed — so no draft or placeholder sheet is offered for download.
Need technical data now? Send your enquiry with the standard and edition you are ordering to.
| Document | Inconel 718 — Plate, sheet & strip technical data sheet |
|---|---|
| Document ID | KS-TDS-N07718-FL |
| Grade | Inconel 718 |
| UNS | N07718 |
| Product form | Plate, sheet and strip |
| Standard | ASTM B670 (current edition B670-25) |
| Status | Under technical review for TDS |
- Technical Data Sheet — Under technical review
Inconel 718 plate — questions buyers ask
Is Inconel 718 the same as Alloy 718?
Alloy 718, UNS N07718, W.Nr 2.4668 are names used for Inconel 718 (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 B670 whichever name is on the enquiry.
What thickness counts as Inconel 718 plate?
Under ASTM B670 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 Inconel 718 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 Inconel 718 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 Inconel 718 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 Inconel 718 plate?
Weight (kg) = length (m) × width (m) × thickness (mm) × 8.19. A 2000 × 1000 × 10 mm plate weighs about 164 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.
Can Inconel 718 plate be supplied to NACE MR0175?
Inconel 718 is covered by NACE MR0175 / ISO 15156-3 within the environmental limits, heat-treatment conditions and hardness limits that standard sets for it. State the requirement on the order so that condition and hardness are verified and reported on the certificate.
Inconel 718 or Inconel 825 — which should I choose?
Inconel 718 is chosen for very high strength at temperatures up to about 650 °C. 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