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Steel A656 Grade 80-N vs A656 Grade 80 TMCP

Steel · A656 Grade 80 temper comparison

A656 Grade 80-N and A656 Grade 80 TMCP are two conditions of the same steel grade, A656 Grade 80: N (normalized) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 580 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (normalized versus thermomechanically controlled processed). A656 Grade 80 TMCP is harder — 220 HB against 205 HB for A656 Grade 80-N — which matters for wear surfaces and threads. A656 Grade 80-N runs hotter in service (400°C vs 350°C continuous).

A656 Grade 80-NChoose it when the part sees heat.

A656 Grade 80 TMCPChoose it when surface hardness matters.

A656 Grade 80-N vs A656 Grade 80 TMCP: properties

A656 Grade 80-NA656 Grade 80 TMCP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

670 MPa97.2 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

580 MPa84.1 ksi
610 MPa88.5 ksi

Compressive Strength

580 MPa84.1 ksi
610 MPa88.5 ksi

Shear Strength

415 MPa60.2 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

295 MPa42.8 ksi
310 MPa45 ksi

Fracture Toughness (K_IC)

115 MPa·√m105 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

205 HB
220 HB

Hardness, Rockwell B

94 HRB
97 HRB

Hardness, Rockwell C

15 HRC
18 HRC

Hardness, Vickers

215 HV
230 HV

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 · Elongation at Break 20% · Reduction in Area 58%

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: 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 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

8.8 % IACS
8.6 % IACS

Electrical Resistivity

1.96×10⁻⁷ Ω·m7.72 µΩ·in
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) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

50 / 100
46 / 100

Machinability Rating (AISI 1212 = 100 %)

57%
53%

Weldability

75 / 100
78 / 100

Formability (cold)

66 / 100
65 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 35 L/kg4.2 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 scaleA656 Grade 80

A656 Grade 80-N vs A656 Grade 80 TMCP — frequently asked

What is the difference between A656 Grade 80-N and A656 Grade 80 TMCP?

A656 Grade 80-N and A656 Grade 80 TMCP are two conditions of the same steel grade, A656 Grade 80: N (normalized) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 580 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (normalized versus thermomechanically controlled processed).

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

HR is the default A656 Grade 80 condition in the FabDigit quote flow (neither N 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.

When should I choose A656 Grade 80-N over A656 Grade 80 TMCP?

Pick A656 Grade 80-N when the part sees heat. Pick A656 Grade 80 TMCP when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A656 Grade 80-N and A656 Grade 80 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.