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Steel 17CrS3 vs 42CrMo4

Steel · grade comparison

Steel 17CrS3 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 490 MPa (71.1 ksi) for 17CrS3, about 12% more; tensile strength follows at 850 MPa (123 ksi) vs 620 MPa (89.9 ksi). 42CrMo4 is the more ductile: elongation 14% versus 10% for 17CrS3, and 42CrMo4 is harder (245 HB vs 190 HB). 42CrMo4 runs hotter in service (400°C vs 250°C continuous). On the shop floor, 17CrS3 machines more easily (good vs fair) and 17CrS3 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).

17CrS3Choose it when the part is machined in volume, or when cost is the deciding factor.

42CrMo4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

17CrS3 vs 42CrMo4: properties

17CrS342CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

490 MPa71.1 ksi
550 MPa79.8 ksi

Elongation at Break

10%
14%

Reduction in Area

45%
40%

Compressive Strength

490 MPa71.1 ksi
560 MPa81.2 ksi

Shear Strength

370 MPa53.7 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
400 MPa58 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

190 HB
245 HB

Hardness, Rockwell B

92 HRB
—

Hardness, Vickers

200 HV
258 HV

Hardness, Rockwell C

—
23 HRC

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Fracture Toughness (K_IC) 75 MPa·√m68.3 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °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

44 W/m·K25.4 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

250°C482 °F
400°C752 °F

Min Service Temperature

-25°C-13 °F
-40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.8 % IACS

Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.6 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

62 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
55%

Weldability

30 / 100
35 / 100

Brazeability / Solderability

60 / 100
50 / 100

Polishability

45 / 100
70 / 100

Same in both: Formability (cold) 35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
108 kN·m/kg

Modulus of Resilience

572 kJ/m³
720 kJ/m³

Thermal Diffusivity

12.2 mm²/s
11.5 mm²/s

Thermal Shock Resistance Index

11
14

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 scale42CrMo417CrS3

Manufacturing and finishing

Capability17CrS342CrMo4
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

17CrS3 vs 42CrMo4 — frequently asked

Is 42CrMo4 stronger than 17CrS3?

Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 490 MPa (71.1 ksi) for 17CrS3 — about 12% more. Tensile strength is 850 MPa (123 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 17CrS3 or 42CrMo4?

17CrS3 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, 17CrS3 or 42CrMo4?

17CrS3. Its machinability rates good (62/100) against fair (50/100) for 42CrMo4; for welding the order is 42CrMo4 first (fair, 35/100) then 17CrS3 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 17CrS3 and 42CrMo4 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.