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Steel 42CrMo4 vs P690QL1

Steel · grade comparison

Steel 42CrMo4 and P690QL1 are both steel grades. P690QL1 is the stronger of the two: yield strength 730 MPa (106 ksi) against 550 MPa (79.8 ksi) for 42CrMo4, about 33% more. P690QL1 is the more ductile: elongation 17% versus 14% for 42CrMo4, and P690QL1 is harder (260 HB vs 245 HB). 42CrMo4 conducts heat better (42.6 W/m·K vs 36 W/m·K). On the shop floor, 42CrMo4 machines more easily (50 vs 40 out of 100), P690QL1 welds better (good vs fair), and P690QL1 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

42CrMo4Choose it when the part is machined in volume.

P690QL1Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

42CrMo4 vs P690QL1: properties

42CrMo4P690QL1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

850 MPa123 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
730 MPa106 ksi

Elongation at Break

14%
17%

Reduction in Area

40%
55%

Compressive Strength

560 MPa81.2 ksi
730 MPa106 ksi

Shear Strength

510 MPa74 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
380 MPa55.1 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

245 HB
260 HB

Hardness, Rockwell C

23 HRC
26 HRC

Hardness, Vickers

258 HV
273 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,440°C2,624 °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
36 W/m·K20.8 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 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

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

Same in both: Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
6.9 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.5×10⁻⁷ Ω·m9.84 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
40 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
45%

Weldability

35 / 100
65 / 100

Formability (cold)

35 / 100
45 / 100

Brazeability / Solderability

50 / 100
40 / 100

Polishability

70 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.3 kg CO₂/kg

Typical Recycled Content

30%
25%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
106 kN·m/kg

Modulus of Resilience

720 kJ/m³
1,269 kJ/m³

Thermal Diffusivity

11.5 mm²/s
10 mm²/s

Thermal Shock Resistance Index

14
12

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 scale42CrMo4P690QL1

Manufacturing and finishing

Capability42CrMo4P690QL1
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 P690QL1 — frequently asked

Is P690QL1 stronger than 42CrMo4?

Yes. P690QL1 has a typical yield strength of 730 MPa (106 ksi) against 550 MPa (79.8 ksi) for 42CrMo4 — about 33% more. Tensile strength is 830 MPa (120 ksi) vs 850 MPa (123 ksi).

Which is cheaper, 42CrMo4 or P690QL1?

P690QL1 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 P690QL1?

42CrMo4, by a small margin. Both rate fair for machinability — 50/100 against 40/100 for P690QL1; for welding the order is P690QL1 first (good, 65/100) then 42CrMo4 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMo4 and P690QL1 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.