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Steel 4J29 vs GX3Ni36

Steel · grade comparison

Steel 4J29 and GX3Ni36 are both steel grades. 4J29 is the stronger of the two: yield strength 345 MPa (50 ksi) against 240 MPa (34.8 ksi) for GX3Ni36, about 44% more; tensile strength follows at 520 MPa (75.4 ksi) vs 450 MPa (65.3 ksi). 4J29 is the more ductile: elongation 30% versus 25% for GX3Ni36, and 4J29 is harder (150 HB vs 130 HB). GX3Ni36 is lighter (8.1 g/cm³ vs 8.36 g/cm³ for 4J29) and 4J29 runs hotter in service (450°C vs 200°C continuous). On the shop floor, 4J29 welds better (very good vs good).

4J29Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

GX3Ni36Choose it when weight is the constraint.

4J29 vs GX3Ni36: properties

4J29GX3Ni36

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

138 GPa20 Msi
140 GPa20.3 Msi

Shear Modulus

52 GPa7.5 Msi
55 GPa8 Msi

Bulk Modulus

126 GPa18.3 Msi
105 GPa15.2 Msi

Poisson's Ratio

0.32
0.29

Tensile Strength (Ultimate)

520 MPa75.4 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
240 MPa34.8 ksi

Elongation at Break

30%
25%

Reduction in Area

65%
33%

Shear Strength

330 MPa47.9 ksi
320 MPa46.4 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
195 MPa28.3 ksi

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

150 HB
130 HB

Hardness, Rockwell B

80 HRB
73 HRB

Hardness, Vickers

155 HV
137 HV

Compressive Strength

—
245 MPa35.5 ksi

Fracture Toughness (K_IC)

—
75 MPa·√m68.3 ksi·√in

Physical

Density and transition temperatures.

Density

8.36 g/cm³0.3 lb/in³
8.1 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,440°C2,624 °F
1,425°C2,597 °F

Same in both: Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

17 W/m·K9.8 BTU/hr·ft·°F
11 W/m·K6.4 BTU/hr·ft·°F

Specific Heat Capacity

439 J/kg·K0.1 BTU/lb·°F
515 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

5.5 µm/m·K3.1 µin/in·°F
2.2 µm/m·K1.2 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
275 J/g118 BTU/lb

Max Service Temperature (continuous)

450°C842 °F
200°C392 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

3.5 % IACS
2.1 % IACS

Electrical Resistivity

4.9×10⁻⁷ Ω·m19.3 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)

-0.5 V
-0.35 V

Same in both: Corrosion Resistance 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

75 / 100
58 / 100

Formability (cold)

80 / 100
20 / 100

Brazeability / Solderability

85 / 100
65 / 100

Polishability

60 / 100
70 / 100

Castability

—
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
90 MJ/kg38,693 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
7 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

20%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

62 kN·m/kg
56 kN·m/kg

Specific Stiffness (E / density)

16.5 MN·m/kg
17.3 MN·m/kg

Modulus of Resilience

431 kJ/m³
206 kJ/m³

Thermal Diffusivity

4.6 mm²/s
2.6 mm²/s

Thermal Shock Resistance Index

12
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 scaleGX3Ni364J29

Manufacturing and finishing

Capability4J29GX3Ni36
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.

4J29 vs GX3Ni36 — frequently asked

Is 4J29 stronger than GX3Ni36?

Yes. 4J29 has a typical yield strength of 345 MPa (50 ksi) against 240 MPa (34.8 ksi) for GX3Ni36 — about 44% more. Tensile strength is 520 MPa (75.4 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 4J29 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, 4J29 or GX3Ni36?

4J29. Its machinability rates fair (35/100) against poor (30/100) for GX3Ni36; for welding the order is 4J29 first (very good, 75/100) then GX3Ni36 (good, 58/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4J29 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.