FabDigit

CP800 vs 4140 and 2 more: properties

CP800414041504340

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi
205 GPa29.7 Msi
205 GPa29.7 Msi

Poisson's Ratio

0.3
0.29
0.29
0.29

Tensile Strength (Ultimate)

840 MPa122 ksi
690 MPa100 ksi
860 MPa125 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
480 MPa69.6 ksi
520 MPa75.4 ksi
620 MPa89.9 ksi

Elongation at Break

13%
22%
16%
18%

Reduction in Area

45%
50%
40%
45%

Compressive Strength

840 MPa122 ksi
480 MPa69.6 ksi
640 MPa92.8 ksi

Shear Strength

520 MPa75.4 ksi
420 MPa60.9 ksi
560 MPa81.2 ksi
580 MPa84.1 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
345 MPa50 ksi
390 MPa56.6 ksi
430 MPa62.4 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
110 MPa·√m100 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
40 J29.5 ft·lbf
25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

250 HB
210 HB
235 HB
285 HB

Hardness, Rockwell B

100 HRB
94 HRB
100 HRB

Hardness, Rockwell C

25 HRC
21 HRC
29 HRC

Hardness, Vickers

265 HV
220 HV
245 HV
300 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,460°C2,660 °F
1,416°C2,581 °F
1,416°C2,581 °F
1,416°C2,581 °F

Liquidus Temperature

1,510°C2,750 °F
1,483°C2,701 °F
1,490°C2,714 °F
1,454°C2,649 °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

38 W/m·K22 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
44.5 W/m·K25.7 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
473 J/kg·K0.11 BTU/lb·°F
473 J/kg·K0.11 BTU/lb·°F
475 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
12.3 µm/m·K6.8 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
250 J/g107 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
425°C797 °F
400°C752 °F
400°C752 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.8 % IACS
7.8 % IACS
7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.48×10⁻⁷ Ω·m9.76 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.61 V
-0.6 V
-0.62 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

35 / 100
60 / 100
45 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
62%
50%
50%

Weldability

70 / 100
40 / 100
25 / 100
33 / 100

Formability (cold)

45 / 100
40 / 100
25 / 100
35 / 100

Polishability

45 / 100
60 / 100
60 / 100
70 / 100

Castability

35 / 100
45 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

28 MJ/kg12,038 BTU/lb
32 MJ/kg13,758 BTU/lb
31 MJ/kg13,328 BTU/lb
32 MJ/kg13,758 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.2 kg CO₂/kg
2.3 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

20%
30%
30%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

107 kN·m/kg
88 kN·m/kg
110 kN·m/kg
121 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

915 kJ/m³
562 kJ/m³
660 kJ/m³
938 kJ/m³

Thermal Diffusivity

10.3 mm²/s
11.5 mm²/s
11.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

13
12
15
17

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 scale414041504340CP800

Manufacturing and finishing

CapabilityCP800414041504340
CNC machiningYesYesYes
Casting & forgingYes
Default conditionCRHRHRHR
Relative cost$$ Standard$$ Standard$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µm
AlCrNYesYesYes
AlTiNYesYesYes
CVD Al2O3YesYesYes
CVD TiCNYesYesYes
CVD TiNYesYesYes
CrNYesYesYes
DLCYesYesYes
HVOF CoatingYesYesYes
MoS2YesYesYes
Multilayer CVDYesYesYes
TiAlNYesYesYes
TiB2YesYesYes
TiCNYesYesYes
TiNYesYesYes
WC/CYesYesYes
ZrNYesYesYes

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

Ready to make it?

Upload a CAD file and FabDigit prices the part in CP800 and 4140 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.