FabDigitFabDigit

Steel 4150 vs S960QL

Steel · grade comparison

Steel 4150 and S960QL are both steel grades, both high strength steel. S960QL is the stronger of the two: yield strength 1,010 MPa (146 ksi) against 520 MPa (75.4 ksi) for 4150, about 94% more; tensile strength follows at 1,050 MPa (152 ksi) vs 860 MPa (125 ksi). In exchange, 4150 is the more ductile: elongation 16% versus 12% for S960QL, and S960QL is harder (320 HB vs 235 HB). 4150 runs hotter in service (400°C vs 350°C continuous) and 4150 conducts heat better (42.6 W/m·K vs 34 W/m·K). On the shop floor, 4150 machines more easily (45 vs 35 out of 100), S960QL welds better (good vs poor), and S960QL sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

S960QLChoose it when strength drives the design, or when it will be welded.

4150 vs S960QL: properties

4150S960QL

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

860 MPa125 ksi
1,050 MPa152 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
1,010 MPa146 ksi

Elongation at Break

16%
12%

Reduction in Area

40%
55%

Shear Strength

560 MPa81.2 ksi
640 MPa92.8 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
470 MPa68.2 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

235 HB
320 HB

Hardness, Rockwell C

21 HRC
34 HRC

Hardness, Vickers

245 HV
340 HV

Compressive Strength

—
1,000 MPa145 ksi

Fracture Toughness (K_IC)

—
100 MPa·√m91 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,460°C2,660 °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
34 W/m·K19.6 BTU/hr·ft·°F

Specific Heat Capacity

473 J/kg·K0.11 BTU/lb·°F
460 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

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

45 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
38%

Weldability

25 / 100
55 / 100

Formability (cold)

25 / 100
40 / 100

Castability

35 / 100
0 / 100

Brazeability / Solderability

55 / 100
30 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
30 MJ/kg12,898 BTU/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
134 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

660 kJ/m³
2,429 kJ/m³

Thermal Diffusivity

11.5 mm²/s
9.4 mm²/s

Thermal Shock Resistance Index

15
14

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 scale4150S960QL

Manufacturing and finishing

Capability4150S960QL
Default conditionHRQ&T
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 S960QL — frequently asked

Is S960QL stronger than 4150?

Yes. S960QL has a typical yield strength of 1,010 MPa (146 ksi) against 520 MPa (75.4 ksi) for 4150 — about 94% more. Tensile strength is 1,050 MPa (152 ksi) vs 860 MPa (125 ksi).

Which is cheaper, 4150 or S960QL?

S960QL 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 S960QL?

4150, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for S960QL; for welding the order is S960QL first (good, 55/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and S960QL 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.