Steel 4J42 CR-H
Supply condition
GB 4J42 · UNS K94100
CR-H = cold Rolled Hard
Highest strength and flatness for thin foil, shims and spring-type contacts; must be annealed if low-expansion accuracy after forming is critical.
Values for the CR-H condition
Other 4J42 tempers and conditions
4J42 is listed in 6 conditions; see the grade overview at 4J42.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault bright/hydrogen annealed soft condition (strip, plate, bar) | Standard stocked condition for glass sealing, deep drawing and lead-frame stamping; gives the specified low, stable expansion coefficient. | 285 | 510 | 35 | 145 HB | — |
Hot rolled | Mill condition for thick plate and forgings; requires stress-relief/annealing before precision machining or sealing. | 300 | 520 | 30 | 155 HB | 2.5 % IACS |
Cold Rolled 1/4 Hard | Pick when annealed strip is too soft to feed/stamp cleanly but good ductility is still needed. | 430 | 580 | 20 | 175 HB | 2.5 % IACS |
Cold drawn | Standard supply state for bar and wire that will be machined into pins, headers and eyelets. | 490 | 630 | 15 | 11 HRC | 2.4 % IACS |
Cold Rolled 1/2 Hard | Use for spring-back-controlled formed parts and stiffer stamped frames/covers. | 560 | 660 | 10 | 17 HRC | 2.5 % IACS |
CR-HThis page Cold Rolled Hard | Highest strength and flatness for thin foil, shims and spring-type contacts; must be annealed if low-expansion accuracy after forming is critical. | 720 | 810 | 3 | 27 HRC | 2.5 % IACS |
What is 4J42 CR-H?
4J42 CR-H is 4J42 supplied in the CR-H condition — highest strength and flatness for thin foil, shims and spring-type contacts; must be annealed if low-expansion accuracy after forming is critical. 4J42 CR-H has a yield strength of 720 MPa (104 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 82% of steel grades. Elongation at break is 3% and the elastic modulus is 150 GPa (21.8 Msi). 4J42 CR-H has a density of 8.12 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; CR-H is available on request or by drawing note.
Advantages
- Good corrosion resistance — 28/100, better than 94% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 720 MPa (104 ksi), better than 82% of steel grades
Limitations
- Limited ductility — 3%, worse than 99% of steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 99% of steel grades
- Low stiffness — 150 GPa (21.8 Msi), worse than 98% of steel grades
- High embodied carbon — 6.6 kg CO₂/kg, worse than 98% of steel grades
- Low electrical conductivity — 2.5 % IACS, worse than 97% of steel grades
4J42 CR-H properties
Typical room-temperature values for 4J42 CR-H; 21 are specific to this condition. Other listed values are 4J42 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4J42 CR-H has a density of 8.12 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
4J42 CR-H has a yield strength of 720 MPa (104 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 82% of steel grades. Elongation at break is 3% and the elastic modulus is 150 GPa (21.8 Msi).
Thermal5
4J42 CR-H is rated for continuous service to 250°C (482 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 99% of steel grades. Thermal expansion is 5.3 µm/m·K (2.94 µin/in·°F).
Electrical3
4J42 CR-H conducts electricity at 2.5 % IACS, worse than 97% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (28/100), better than 94% of steel grades.
Sustainability4
Producing a kilogram of 4J42 CR-H takes about 70 MJ of energy and emits 6.6 kg of CO₂ — more than 97% of steel grades. Typical recycled content is 35%.
Manufacturability7
4J42 CR-H's machinability is fair (45/100, worse than 65% of steel grades); weldability good (55/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4J42 CR-H
Is 4J42 easy to machine?
Gummy and work-hardening like austenitic stainless: use sharp positive-rake carbide, rigid setups, low speed/high feed and flood coolant; avoid dwelling to prevent glazing.
Can 4J42 be welded?
Resistance, laser and GTAW welding are routine with matching Fe-42Ni filler; keep heat input low and interpass clean, since carbon/sulfur pickup causes porosity and gas leakage in seals.
Can 4J42 be formed, bent or molded?
Excellent deep-drawing and stamping in the annealed state; interstage anneal for severe draws and always re-anneal (with controlled H₂/vacuum cycle) before glass sealing to restore expansion accuracy.
What surface finishes work on 4J42?
Not anodizable — protect with electroplated Ni, Ni+Au, Ag or Sn; oxidize the surface in a controlled wet-H₂/air cycle before glass-to-metal sealing to form the adherent bonding oxide.
4J42 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Nicontrols expansion coefficient | 41.5 – 42.5 | 42 |
| C | ≤ 0.05 | 0.03 |
| Si | ≤ 0.3 | 0.15 |
| Mn | 0.2 – 0.6 | 0.4 |
| P | ≤ 0.02 | — |
| S | ≤ 0.02 | — |
| Crresidual | ≤ 0.1 | — |
| Curesidual | ≤ 0.2 | — |
| Fe | balance | — |
4J42 CR-H — frequently asked
What is 4J42 CR-H used for?
4J42 CR-H is typically used for IC lead frames, electronic component headers and glass-metal seals. In short: 42Ni lead-frame alloy; alloy 42 equivalent; soft-glass sealing strip.
What is the yield strength of 4J42 CR-H?
4J42 CR-H has a typical yield strength of 720 MPa (104 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 82% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 4J42 CR-H easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Gummy and work-hardening like austenitic stainless: use sharp positive-rake carbide, rigid setups, low speed/high feed and flood coolant; avoid dwelling to prevent glazing.
Can 4J42 CR-H be welded?
Yes — weldability is rated good (55/100). Resistance, laser and GTAW welding are routine with matching Fe-42Ni filler; keep heat input low and interpass clean, since carbon/sulfur pickup causes porosity and gas leakage in seals.
What surface finishes work on 4J42 CR-H?
Not anodizable — protect with electroplated Ni, Ni+Au, Ag or Sn; oxidize the surface in a controlled wet-H₂/air cycle before glass-to-metal sealing to form the adherent bonding oxide.
Can 4J42 CR-H be formed, bent or molded?
Excellent deep-drawing and stamping in the annealed state; interstage anneal for severe draws and always re-anneal (with controlled H₂/vacuum cycle) before glass sealing to restore expansion accuracy.
What is the maximum service temperature of 4J42 CR-H?
4J42 CR-H is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4J42 Annealed and 4J42 CR-H?
Annealed is the default condition — standard stocked condition for glass sealing, deep drawing and lead-frame stamping; gives the specified low, stable expansion coefficient. CR-H: highest strength and flatness for thin foil, shims and spring-type contacts; must be annealed if low-expansion accuracy after forming is critical. Yield strength is 285 MPa in Annealed versus 720 MPa in CR-H.
Sources
- ASM Handbook Vol. 2 — Properties of Controlled-Expansion Alloys (Alloy 42) — ASM International (1990)
- Alloy 42 / Nilo 42 controlled-expansion strip datasheet — Carpenter / Special Metals (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.