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Steel A242 vs X65

Steel · grade comparison

Steel A242 and X65 are both steel grades. X65 is the stronger of the two: yield strength 495 MPa (71.8 ksi) against 370 MPa (53.7 ksi) for A242, about 34% more; tensile strength follows at 570 MPa (82.7 ksi) vs 510 MPa (74 ksi). X65 is the more ductile: elongation 32% versus 24% for A242, and X65 is harder (180 HB vs 155 HB). A242 runs hotter in service (350°C vs 250°C continuous). On the shop floor, X65 welds better (excellent vs very good).

A242Choose it when the part sees heat.

X65Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

A242 vs X65: properties

A242X65

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
207 GPa30 Msi

Shear Modulus

79 GPa11.5 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

510 MPa74 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
495 MPa71.8 ksi

Elongation at Break

24%
32%

Reduction in Area

50%
68%

Compressive Strength

370 MPa53.7 ksi
495 MPa71.8 ksi

Shear Strength

320 MPa46.4 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
270 MPa39.2 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
200 MPa·√m182 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
260 J192 ft·lbf

Hardness, Brinell

155 HB
180 HB

Hardness, Rockwell B

82 HRB
89 HRB

Hardness, Vickers

163 HV
190 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,425°C2,597 °F

Liquidus Temperature

1,510°C2,750 °F
1,505°C2,741 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
47 W/m·K27.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
250°C482 °F

Min Service Temperature

-30°C-22 °F
-45°C-49 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8.6 % IACS

Same in both: Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.68 V

Corrosion Resistance

35 / 100
12 / 100

Manufacturability

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

Machinability

58 / 100
55 / 100

Weldability

80 / 100
90 / 100

Formability (cold)

65 / 100
70 / 100

Brazeability / Solderability

40 / 100
45 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 60% · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Typical Recycled Content

30%
20%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

342 kJ/m³
592 kJ/m³

Thermal Diffusivity

13 mm²/s
12.7 mm²/s

Thermal Shock Resistance Index

10
11

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 scaleA242X65

Manufacturing and finishing

CapabilityA242X65
Default condition——
Relative cost$ Budget$ Budget
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.

A242 vs X65 — frequently asked

Is X65 stronger than A242?

Yes. X65 has a typical yield strength of 495 MPa (71.8 ksi) against 370 MPa (53.7 ksi) for A242 — about 34% more. Tensile strength is 570 MPa (82.7 ksi) vs 510 MPa (74 ksi).

Which is cheaper, A242 or X65?

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

Which welds better, A242 or X65?

X65. Its weldability rates excellent (90/100) against very good (80/100) for A242.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A242 and X65 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.