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Steel 4340 vs MS1500

Steel · grade comparison

Steel 4340 and MS1500 are both steel grades, both high strength steel. MS1500 is the stronger of the two: yield strength 1,250 MPa (181 ksi) against 620 MPa (89.9 ksi) for 4340, about 102% more; tensile strength follows at 1,550 MPa (225 ksi) vs 950 MPa (138 ksi). In exchange, 4340 is the more ductile: elongation 18% versus 5% for MS1500, and MS1500 is harder (46 HRC vs 29 HRC). 4340 runs hotter in service (400°C vs 200°C continuous) and 4340 conducts heat better (44.5 W/m·K vs 30 W/m·K). On the shop floor, 4340 machines more easily (fair vs poor), MS1500 welds better (fair vs poor), and MS1500 sits in a lower cost tier (standard, $$) than 4340 (premium, $$$).

4340Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

MS1500Choose it when strength drives the design, or when it will be welded.

4340 vs MS1500: properties

4340MS1500

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

950 MPa138 ksi
1,550 MPa225 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
1,250 MPa181 ksi

Elongation at Break

18%
5%

Reduction in Area

45%
—

Compressive Strength

640 MPa92.8 ksi
—

Shear Strength

580 MPa84.1 ksi
930 MPa135 ksi

Fatigue Strength (Endurance Limit)

430 MPa62.4 ksi
650 MPa94.3 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
—

Hardness, Brinell

285 HB
—

Hardness, Rockwell B

100 HRB
—

Hardness, Rockwell C

29 HRC
46 HRC

Hardness, Vickers

300 HV
470 HV

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

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,425°C2,597 °F

Liquidus Temperature

1,454°C2,649 °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

44.5 W/m·K25.7 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Specific Heat Capacity

475 J/kg·K0.11 BTU/lb·°F
470 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

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

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

7 % IACS
8 % IACS

Electrical Resistivity

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.6 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

48 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
15%

Weldability

33 / 100
50 / 100

Formability (cold)

35 / 100
18 / 100

Castability

45 / 100
—

Brazeability / Solderability

55 / 100
—

Polishability

70 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Water

60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

121 kN·m/kg
197 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

938 kJ/m³
3,720 kJ/m³

Thermal Diffusivity

11.9 mm²/s
8.1 mm²/s

Thermal Shock Resistance Index

17
18

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 scale4340MS1500

Manufacturing and finishing

Capability4340MS1500
CNC machiningYes—
Default conditionHRCR
Relative cost$$$ Premium$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

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.

4340 vs MS1500 — frequently asked

Is MS1500 stronger than 4340?

Yes. MS1500 has a typical yield strength of 1,250 MPa (181 ksi) against 620 MPa (89.9 ksi) for 4340 — about 102% more. Tensile strength is 1,550 MPa (225 ksi) vs 950 MPa (138 ksi).

Which is cheaper, 4340 or MS1500?

MS1500 is the lower-cost material: it sits in the standard tier ($$) while 4340 is premium ($$$). 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, 4340 or MS1500?

4340. Its machinability rates fair (48/100) against poor (22/100) for MS1500; for welding the order is MS1500 first (fair, 50/100) then 4340 (poor, 33/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4340 and MS1500 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.