Physical properties
| Density | 8.73 | g/cm³ |
Informative values: they vary with composition, condition and test method. Use the governing standard or measured mill data for pressure and heat-transfer calculations.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements6 elements | |||
| Ni | Nickel | Bal. | |
| Cr | Chromium | 19 – 23% | |
| Mo | Molybdenum | 15 – 17% | |
| Fe | Iron | ≤ 5% | |
| W | Tungsten | 3 – 4.4% | |
| Ti | Titanium | 0.02 – 0.25% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual5 elements | |||
| C | Carbon | ≤ 0.01% | |
| Si | Silicon | ≤ 0.08% | |
| Mn | Manganese | ≤ 0.75% | |
| P | Phosphorus | ≤ 0.04% | |
| S | Sulphur | ≤ 0.02% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Bar and rod | Hot- or cold-finished, solution annealed | ≥ 690 (100 ksi) | ≥ 310 (45 ksi) | ≥ 45 | |
| Bar and rod | Cold-worked, Grade 1 | ≥ 827 (120 ksi) | ≥ 586 (85 ksi) | ≥ 20 | |
| Bar and rod | Cold-worked, Grade 2 | ≥ 931 (135 ksi) | ≥ 862 (125 ksi) | ≥ 20 | |
| Bar and rod | Cold-worked, Grade 3 | ≥ 1103 (160 ksi) | ≥ 1034 (150 ksi) | ≥ 20 | |
| Forgings, flanges, fittings and valve parts | Solution annealed | ≥ 690 (100 ksi) | ≥ 310 (45 ksi) | ≥ 45 | |
| Plate, sheet and strip | |||||
| Plate, sheet and strip | Solution annealed | ≥ 690 (100 ksi) | ≥ 310 (45 ksi) | ≥ 45 | |
| Tube and pipe | |||||
| Seamless pipe and tube | Solution annealed and descaled | ≥ 690 (100 ksi) | ≥ 310 (45 ksi) | ≥ 45 | |
| Fittings and flanges | |||||
| Fittings (factory-made wrought butt-weld / socket) | 2150 °F [1177 °C], rapid air or water quench | — | — | — | Recommended temperature; tolerance ±15 °C (±25 °F). Tensile properties follow the starting material. No tension test on the finished fitting unless agreed. |
Grain size
Required by the standard, conditionally
| Form and thickness | ASTM micrograin size | Mean grain diameter |
|---|---|---|
| Sheet & strip ≤3.175 mm | No. 3.0 or finer | 0.127 mm |
| Sheet & strip >3.175 mm | No. 1.5 or finer | 0.214 mm |
Mandatory, with no "when specified by the purchaser" qualifier; but it covers sheet and strip only — plate is not subject to it.
More detail 2
The direction is "or finer", the opposite of the "No. 5 or coarser" of 800H and 800HT.
⚠ The 100 HRB max hardness is INFORMATIVE only — grain size binds, hardness does not.
Where this grade is recommended
Matched in 1 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Wet Cl₂, chlor-alkali | Chemical Processing | 80 – 150 °C | 3 / 11 | 93 |
Designations & equivalents
| W.Nr. (Germany) | 2.4606 |
| EN designation | NiCr21Mo16W |
| Trade name(s) | Inconel 686 / Nicrofer 5716 |
| ASTM / AISI | B163 / B366 / B462 / B564 / B574 / B575 / B619 / B622 / B626 / B751 / B775 / B829 / B906 |
| AWS (welding) | A5.14 ERNiCrMo-14 / A5.11 ENiCrMo-14 |
| NACE sour service | ISO 15156-3: annealed, no limit on H₂S or temperature; cold-worked ≤40 HRC |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
10 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is Alloy 686 · UNS N06686?
Alloy 686 · UNS N06686 — Ni corrosion-resistant. Super C-family corrosion resistance — FGD and wet-chlorine extremes
What is the maximum service temperature of N06686?
Typically about 540 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of N06686?
The specified minimum tensile strength is 690 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover N06686?
ASTM B575, ASTM B574, ASTM B622, ASTM B619, ASTM B626, ASTM B163, ASTM B564 (forgings), ASTM B462, ASTM B472, ASTM B366
Where is N06686 typically used?
Wet Cl₂, chlor-alkali (Chemical Processing)
In which forms is N06686 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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