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Steel SM570-QT vs SM570 TMCP

Steel · SM570 temper comparison

SM570-QT and SM570 TMCP are two conditions of the same steel grade, SM570: QT (quenched and tempered) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. SM570-QT is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 500 MPa (72.5 ksi) for SM570 TMCP, about 6% more; tensile strength follows at 660 MPa (95.7 ksi) vs 625 MPa (90.6 ksi). On the shop floor, SM570 TMCP welds better (very good vs good) and SM570 TMCP forms better (good vs fair).

SM570-QTChoose it when strength drives the design.

SM570 TMCPChoose it when it will be welded.

SM570-QT vs SM570 TMCP: properties

SM570-QTSM570 TMCP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

660 MPa95.7 ksi
625 MPa90.6 ksi

Yield Strength (0.2% offset)

530 MPa76.9 ksi
500 MPa72.5 ksi

Elongation at Break

23%
25%

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
290 MPa42.1 ksi

Fracture Toughness (K_IC)

145 MPa·√m132 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

130 J95.9 ft·lbf
150 J111 ft·lbf

Hardness, Brinell

205 HB
195 HB

Hardness, Rockwell B

95 HRB
92 HRB

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55% · Compressive Strength 490 MPa71.1 ksi · Shear Strength 390 MPa56.6 ksi · Hardness, Vickers 200 HV

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

-20°C-4 °F
-40°C-40 °F

Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 470 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 8.6 % IACS · Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

50%
55%

Weldability

68 / 100
82 / 100

Formability (cold)

48 / 100
58 / 100

Same in both: Machinability 52 / 100 · Brazeability / Solderability 55 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

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 scaleSM570

SM570-QT vs SM570 TMCP — frequently asked

Is SM570-QT stronger than SM570 TMCP?

Yes. SM570-QT has a typical yield strength of 530 MPa (76.9 ksi) against 500 MPa (72.5 ksi) for SM570 TMCP — about 6% more. Tensile strength is 660 MPa (95.7 ksi) vs 625 MPa (90.6 ksi).

Which condition does FabDigit quote by default, QT or TMCP?

N is the default SM570 condition in the FabDigit quote flow (neither QT 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 welds better, SM570-QT or SM570 TMCP?

SM570 TMCP. Its weldability rates very good (82/100) against good (68/100) for SM570-QT.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SM570-QT and SM570 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.