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Steel 4150 vs HSLA

Steel · grade comparison

Steel 4150 and HSLA are both steel grades, both high strength steel. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 345 MPa (50 ksi) for HSLA, about 51% more; tensile strength follows at 860 MPa (125 ksi) vs 490 MPa (71.1 ksi). In exchange, HSLA is the more ductile: elongation 21% versus 16% for 4150, and 4150 is harder (235 HB vs 150 HB). HSLA conducts electricity better (9 % IACS vs 7.8 % IACS). On the shop floor, HSLA machines more easily (good vs fair), HSLA welds better (very good vs poor), and HSLA sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when strength drives the design.

HSLAChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

4150 vs HSLA: properties

4150HSLA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
490 MPa71.1 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
345 MPa50 ksi

Elongation at Break

16%
21%

Reduction in Area

40%
50%

Shear Strength

560 MPa81.2 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
240 MPa34.8 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

235 HB
150 HB

Hardness, Rockwell C

21 HRC
—

Hardness, Vickers

245 HV
158 HV

Compressive Strength

—
345 MPa50 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

Hardness, Rockwell B

—
80 HRB

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °F
1,510°C2,750 °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

42.6 W/m·K24.6 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Specific Heat Capacity

473 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

Latent Heat of Fusion

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

Same in both: Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
9 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Corrosion Resistance

12 / 100
16 / 100

Manufacturability

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

Machinability

45 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
60%

Weldability

25 / 100
80 / 100

Formability (cold)

25 / 100
60 / 100

Castability

35 / 100
30 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

60 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
62 kN·m/kg

Modulus of Resilience

660 kJ/m³
290 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.2 mm²/s

Thermal Shock Resistance Index

15
9

Same in both: Specific Stiffness (E / density) 26.1 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 scale4150HSLA

Manufacturing and finishing

Capability4150HSLA
Default conditionHRHR
Relative cost$$$ Premium$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

4150 vs HSLA — frequently asked

Is 4150 stronger than HSLA?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 345 MPa (50 ksi) for HSLA — about 51% more. Tensile strength is 860 MPa (125 ksi) vs 490 MPa (71.1 ksi).

Which is cheaper, 4150 or HSLA?

HSLA is the lower-cost material: it sits in the standard tier ($$) while 4150 is premium ($$$). 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, 4150 or HSLA?

HSLA. Its machinability rates good (58/100) against fair (45/100) for 4150; for welding the order is HSLA first (very good, 80/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and HSLA 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.