Chemical composition
Nominal: elements given only as a maximum are counted at the cap; the balance takes the remainder.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements3 elements | |||
| Fe | Iron (nominal) | 53% | |
| Ni | Nickel (nominal) | 29% | |
| Co | Cobalt (nominal) | 17% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual9 elements | |||
| Mn | Manganese | ≤ 0.5% | |
| Si | Silicon | ≤ 0.2% | |
| C | Carbon | ≤ 0.04% | |
| Al | Aluminium | ≤ 0.1% | |
| Mg | Magnesium | ≤ 0.1% | |
| Zr | Zirconium | ≤ 0.1% | |
| Ti | Titanium | ≤ 0.1% | |
| Cu | Copper | ≤ 0.2% | |
| Cr | Chromium | ≤ 0.2% | |
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 |
|---|---|---|---|---|---|
| Plate, sheet and strip | |||||
| Plate and strip | Annealed | ≤ 570 | — | — | |
| Plate and strip | B, 1/4 hard | 520 – 630 | — | — | |
| Plate and strip | E, hard | ≥ 700 (102 ksi) | — | — | |
| Several forms | |||||
| Wire and bar | Annealed | ≤ 585 | — | — | |
| Other | |||||
| Thermal-expansion test specimens | After the specified hydrogen heat treatment | — | — | — | Also specified: CTE 30–400 °C 4.6 – 5.2 ×10⁻⁶/K · CTE 30–450 °C 5.1 – 5.5 ×10⁻⁶/K |
Where this grade is recommended
Matched in 2 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Vacuum electronics | Semiconductor & Vac-Electronics | ≤ 400 °C | 2 / 8 | 92 |
| Lead frames & packaging | Semiconductor & Vac-Electronics | Reflow 300 – 450 °C | 2 / 6 | 89 |
Designations & equivalents
| UNS | K94610 |
| W.Nr. (Germany) | 1.3981 |
| EN designation | NiCo29-18 |
| Trade name(s) | Kovar / Nilo K / Dilver P / Vacon 12 / Rodar |
| ASTM / AISI | ASTM F15 |
| GOST (Russia) | ≈ 29НК |
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
Name the standard and its edition on the order.
Frequently asked questions
What is Kovar 4J29 (ASTM F15)?
Kovar 4J29 (ASTM F15) — Precision alloys. Expansion-matched to hard glass and ceramics — vacuum-tight seals and package leads
What is the maximum service temperature of 4J29?
Typically about 450 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
Which standards cover 4J29?
ASTM F15
Where is 4J29 typically used?
Vacuum electronics (Semiconductor & Vac-Electronics); Lead frames & packaging (Semiconductor & Vac-Electronics)
In which forms is 4J29 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
Or email us: info@kochlin.com