Steel SM490A-SR vs SM490A TMCP
Steel · SM490A temper comparison
SM490A-SR and SM490A TMCP are two conditions of the same steel grade, SM490A: SR (stress relieved) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. SM490A TMCP is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 350 MPa (50.8 ksi) for SM490A-SR, about 10% more. SM490A TMCP is harder — 160 HB against 148 HB for SM490A-SR — which matters for wear surfaces and threads.
SM490A TMCPChoose it when strength drives the design, or when surface hardness matters.
SM490A-SR vs SM490A TMCP: 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
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 55 / 100 · Polishability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 30%
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.
SM490A-SR vs SM490A TMCP — frequently asked
Is SM490A TMCP stronger than SM490A-SR?
Yes. SM490A TMCP has a typical yield strength of 385 MPa (55.8 ksi) against 350 MPa (50.8 ksi) for SM490A-SR — about 10% more. Tensile strength is 545 MPa (79 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, SR or TMCP?
AR is the default SM490A condition in the FabDigit quote flow (neither SR nor TMCP). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, SM490A-SR or SM490A TMCP?
SM490A-SR, by a small margin. Both rate good for machinability — 61/100 against 56/100 for SM490A TMCP; for welding the order is SM490A TMCP first (excellent, 93/100) then SM490A-SR (excellent, 88/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SM490A-SR and SM490A TMCP 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.