Steel 42CrMo4 vs 8CrMo16-5
Steel · grade comparison
Steel 42CrMo4 and 8CrMo16-5 are both steel grades. 8CrMo16-5 is the stronger of the two: yield strength 590 MPa (85.6 ksi) against 550 MPa (79.8 ksi) for 42CrMo4, about 7% more. 8CrMo16-5 is the more ductile: elongation 16% versus 14% for 42CrMo4, and 8CrMo16-5 is harder (25 HRC vs 23 HRC). 8CrMo16-5 runs hotter in service (500°C vs 400°C continuous) and 42CrMo4 conducts heat better (42.6 W/m·K vs 34 W/m·K).
8CrMo16-5Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
42CrMo4 vs 8CrMo16-5: 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.
Shear 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 C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Brazeability / Solderability
Same in both: Machinability Rating (AISI 1212 = 100 %) 55% · Weldability 35 / 100 · Formability (cold) 35 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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 | 42CrMo4 | 8CrMo16-5 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | HR | — |
| Relative cost | $$ Standard | $$ 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.
42CrMo4 vs 8CrMo16-5 — frequently asked
Is 8CrMo16-5 stronger than 42CrMo4?
Yes. 8CrMo16-5 has a typical yield strength of 590 MPa (85.6 ksi) against 550 MPa (79.8 ksi) for 42CrMo4 — about 7% more. Tensile strength is 800 MPa (116 ksi) vs 850 MPa (123 ksi).
Which is cheaper, 42CrMo4 or 8CrMo16-5?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 42CrMo4 or 8CrMo16-5?
8CrMo16-5. Its machinability rates good (55/100) against fair (50/100) for 42CrMo4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 42CrMo4 and 8CrMo16-5 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.