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Steel 42CrMo4 vs P500Q

Steel · grade comparison

Steel 42CrMo4 and P500Q are both steel grades. 42CrMo4 is the stronger of the two: tensile strength 850 MPa (123 ksi) against 660 MPa (95.7 ksi) for P500Q, about 29% more. In exchange, P500Q is the more ductile: elongation 20% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 215 HB). 42CrMo4 conducts heat better (42.6 W/m·K vs 38 W/m·K). On the shop floor, P500Q welds better (very good vs fair) and P500Q sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when strength drives the design.

P500QChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

42CrMo4 vs P500Q: properties

42CrMo4P500Q

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

850 MPa123 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
545 MPa79 ksi

Elongation at Break

14%
20%

Reduction in Area

40%
58%

Compressive Strength

560 MPa81.2 ksi
545 MPa79 ksi

Shear Strength

510 MPa74 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

245 HB
215 HB

Hardness, Rockwell C

23 HRC
19 HRC

Hardness, Vickers

258 HV
225 HV

Hardness, Rockwell B

—
95 HRB

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,495°C2,723 °F
1,500°C2,732 °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

42.6 W/m·K24.6 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Specific Heat Capacity

473 J/kg·K0.11 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
12.2 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Min Service Temperature

-40°C-40 °F
0°C32 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.62 V

Corrosion Resistance

12 / 100
13 / 100

Manufacturability

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

Machinability

50 / 100
45 / 100

Weldability

35 / 100
70 / 100

Formability (cold)

35 / 100
45 / 100

Brazeability / Solderability

50 / 100
—

Polishability

70 / 100
50 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 55%

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
84 kN·m/kg

Modulus of Resilience

720 kJ/m³
707 kJ/m³

Thermal Diffusivity

11.5 mm²/s
10.5 mm²/s

Thermal Shock Resistance Index

14
10

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg

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 scale42CrMo4P500Q

Manufacturing and finishing

Capability42CrMo4P500Q
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$ Standard$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

42CrMo4 vs P500Q — frequently asked

Is 42CrMo4 stronger than P500Q?

Yes. 42CrMo4 has a typical tensile strength of 850 MPa (123 ksi) against 660 MPa (95.7 ksi) for P500Q — about 29% more.

Which is cheaper, 42CrMo4 or P500Q?

P500Q is the lower-cost material: it sits in the budget tier ($) while 42CrMo4 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 42CrMo4 or P500Q?

42CrMo4, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for P500Q; for welding the order is P500Q first (very good, 70/100) then 42CrMo4 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and P500Q 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.