Steel 17Cr3 vs 42CrMo4
Steel · grade comparison
Steel 17Cr3 and 42CrMo4 are both steel grades. 42CrMo4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 360 MPa (52.2 ksi) for 17Cr3, about 53% more; tensile strength follows at 850 MPa (123 ksi) vs 590 MPa (85.6 ksi). In exchange, 17Cr3 is the more ductile: elongation 20% versus 14% for 42CrMo4, and 42CrMo4 is harder (245 HB vs 170 HB). 42CrMo4 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 17Cr3 machines more easily (good vs fair), 17Cr3 welds better (good vs fair), and 17Cr3 sits in a lower cost tier (budget, $) than 42CrMo4 (standard, $$).
17Cr3Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
42CrMo4Choose it when strength drives the design, or when the part sees heat.
17Cr3 vs 42CrMo4: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Melting Point (Solidus)
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 17Cr3 | 42CrMo4 |
|---|---|---|
| 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.
17Cr3 vs 42CrMo4 — frequently asked
Is 42CrMo4 stronger than 17Cr3?
Yes. 42CrMo4 has a typical yield strength of 550 MPa (79.8 ksi) against 360 MPa (52.2 ksi) for 17Cr3 — about 53% more. Tensile strength is 850 MPa (123 ksi) vs 590 MPa (85.6 ksi).
Which is cheaper, 17Cr3 or 42CrMo4?
17Cr3 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, 17Cr3 or 42CrMo4?
17Cr3. Its machinability rates good (62/100) against fair (50/100) for 42CrMo4; for welding the order is 17Cr3 first (good, 60/100) then 42CrMo4 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 17Cr3 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.