Steel 4140 vs HSLA
Steel · grade comparison
Steel 4140 and HSLA are both steel grades, both high strength steel. 4140 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 345 MPa (50 ksi) for HSLA, about 39% more; tensile strength follows at 690 MPa (100 ksi) vs 490 MPa (71.1 ksi). 4140 is harder — 210 HB against 150 HB for HSLA — which matters for wear surfaces and threads. HSLA conducts electricity better (9 % IACS vs 7.8 % IACS). On the shop floor, HSLA welds better (very good vs fair) and HSLA forms better (good vs fair).
4140Choose it when strength drives the design, or when surface hardness matters.
HSLAChoose it when it will be welded.
4140 vs HSLA: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
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 · Reduction in Area 50% · Charpy V-Notch Impact (RT) 40 J29.5 ft·lbf
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 4140 | HSLA |
|---|---|---|
| Casting & forging | Yes | — |
| Default condition | HR | HR |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 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.
4140 vs HSLA — frequently asked
Is 4140 stronger than HSLA?
Yes. 4140 has a typical yield strength of 480 MPa (69.6 ksi) against 345 MPa (50 ksi) for HSLA — about 39% more. Tensile strength is 690 MPa (100 ksi) vs 490 MPa (71.1 ksi).
Which is cheaper, 4140 or HSLA?
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 welds better, 4140 or HSLA?
HSLA. Its weldability rates very good (80/100) against fair (40/100) for 4140.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4140 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.