Chemical composition
Nominal: elements given only as a maximum are counted at the cap; the balance takes the remainder.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements2 elements | |||
| Fe | Iron | Bal. | |
| Ni | Nickel (nominal) | 41% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual7 elements | |||
| Mn | Manganese | ≤ 0.8% | |
| Si | Silicon | ≤ 0.3% | |
| C | Carbon | ≤ 0.05% | |
| Co | Cobalt | ≤ 0.5% | |
| Cr | Chromium | ≤ 0.1% | |
| P | Phosphorus | ≤ 0.025% | |
| S | Sulphur | ≤ 0.025% | |
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 ≥ % |
|---|---|---|---|---|
| Plate, strip, wire and bar for glass-to-metal sealing | Annealed | ≤ 586 | — | — |
| Plate, strip, wire and bar for glass-to-metal sealing | 1/4 hard | ≤ 793 | — | — |
| Plate, strip, wire and bar for glass-to-metal sealing | 1/2 hard | ≤ 862 | — | — |
| Plate, strip, wire and bar for glass-to-metal sealing | Full hard | ≥ 827 (120 ksi) | — | — |
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 |
|---|---|---|---|---|
| Lead frames & packaging | Semiconductor & Vac-Electronics | Reflow 300 – 450 °C | 1 / 6 | 91 |
| Metrology & precision structures | Semiconductor & Vac-Electronics | Controlled 20 °C | 4 / 4 | 78 |
Designations & equivalents
| UNS | K94100 |
| W.Nr. (Germany) | 1.3917 |
| EN designation | FeNi42 |
| Trade name(s) | Alloy 42 / Nilo 42 / Pernifer 42 |
| ASTM / AISI | ASTM F30 |
| GOST (Russia) | ≈ 42Н |
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
2 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 42 (4J42)?
Alloy 42 (4J42) — Precision alloys. Matched to soft glass and ceramics — lead frames and sealing leads
What is the maximum service temperature of 4J42?
Typically about 400 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
Which standards cover 4J42?
MIL-I-23011C Class 5 / ASTM F30 Alloy No.42, ASTM F30
Where is 4J42 typically used?
Lead frames & packaging (Semiconductor & Vac-Electronics); Metrology & precision structures (Semiconductor & Vac-Electronics)
In which forms is 4J42 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