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Steel 4J42 vs GX3Ni36

Steel · grade comparison

Steel 4J42 and GX3Ni36 are both steel grades. 4J42 is the stronger of the two: yield strength 285 MPa (41.3 ksi) against 240 MPa (34.8 ksi) for GX3Ni36, about 19% more; tensile strength follows at 510 MPa (74 ksi) vs 450 MPa (65.3 ksi). 4J42 is the more ductile: elongation 35% versus 25% for GX3Ni36, and 4J42 is harder (145 HB vs 130 HB). 4J42 runs hotter in service (400°C vs 200°C continuous) and 4J42 conducts heat better (12.6 W/m·K vs 11 W/m·K). On the shop floor, 4J42 welds better (very good vs good).

4J42Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

4J42 vs GX3Ni36: properties

4J42GX3Ni36

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

145 GPa21 Msi
140 GPa20.3 Msi

Shear Modulus

57 GPa8.3 Msi
55 GPa8 Msi

Bulk Modulus

106 GPa15.4 Msi
105 GPa15.2 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

510 MPa74 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

285 MPa41.3 ksi
240 MPa34.8 ksi

Elongation at Break

35%
25%

Reduction in Area

60%
33%

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
195 MPa28.3 ksi

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

145 HB
130 HB

Hardness, Rockwell B

78 HRB
73 HRB

Hardness, Vickers

150 HV
137 HV

Compressive Strength

—
245 MPa35.5 ksi

Fracture Toughness (K_IC)

—
75 MPa·√m68.3 ksi·√in

Same in both: Shear Strength 320 MPa46.4 ksi

Physical

Density and transition temperatures.

Density

8.12 g/cm³0.29 lb/in³
8.1 g/cm³0.29 lb/in³

Same in both: Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

12.6 W/m·K7.3 BTU/hr·ft·°F
11 W/m·K6.4 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
515 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

5.3 µm/m·K2.9 µin/in·°F
2.2 µm/m·K1.2 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Latent Heat of Fusion

—
275 J/g118 BTU/lb

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.5 % IACS
2.1 % IACS

Electrical Resistivity

7×10⁻⁷ Ω·m27.6 µΩ·in
8.2×10⁻⁷ Ω·m32.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.4 V
-0.35 V

Corrosion Resistance

28 / 100
25 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

35 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
25%

Weldability

70 / 100
58 / 100

Formability (cold)

85 / 100
20 / 100

Brazeability / Solderability

80 / 100
65 / 100

Castability

—
50 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

70 MJ/kg30,095 BTU/lb
90 MJ/kg38,693 BTU/lb

Embodied Carbon (primary production)

6.6 kg CO₂/kg
7 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

35%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

63 kN·m/kg
56 kN·m/kg

Specific Stiffness (E / density)

17.9 MN·m/kg
17.3 MN·m/kg

Modulus of Resilience

280 kJ/m³
206 kJ/m³

Thermal Diffusivity

3.1 mm²/s
2.6 mm²/s

Thermal Shock Resistance Index

8
16

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleGX3Ni364J42

Manufacturing and finishing

Capability4J42GX3Ni36
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

4J42 vs GX3Ni36 — frequently asked

Is 4J42 stronger than GX3Ni36?

Yes. 4J42 has a typical yield strength of 285 MPa (41.3 ksi) against 240 MPa (34.8 ksi) for GX3Ni36 — about 19% more. Tensile strength is 510 MPa (74 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 4J42 or GX3Ni36?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 4J42 or GX3Ni36?

4J42. Its machinability rates fair (35/100) against poor (30/100) for GX3Ni36; for welding the order is 4J42 first (very good, 70/100) then GX3Ni36 (good, 58/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4J42 and GX3Ni36 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.