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Steel A656 Grade 80-HR vs A656 Grade 80 TMCP

Steel · A656 Grade 80 temper comparison

A656 Grade 80-HR and A656 Grade 80 TMCP are two conditions of the same steel grade, A656 Grade 80: HR (hot rolled) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 590 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus thermomechanically controlled processed). A656 Grade 80 TMCP is the more ductile: elongation 20% versus 18% for A656 Grade 80-HR, and A656 Grade 80 TMCP is harder (18 HRC vs 17 HRC).

A656 Grade 80 TMCPChoose it when the part is bent, formed or impact-loaded.

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

A656 Grade 80-HRA656 Grade 80 TMCP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

680 MPa98.6 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

590 MPa85.6 ksi
610 MPa88.5 ksi

Elongation at Break

18%
20%

Reduction in Area

52%
58%

Compressive Strength

590 MPa85.6 ksi
610 MPa88.5 ksi

Shear Strength

420 MPa60.9 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
310 MPa45 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

215 HB
220 HB

Hardness, Rockwell B

96 HRB
97 HRB

Hardness, Rockwell C

17 HRC
18 HRC

Hardness, Vickers

225 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

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

45 W/m·K26 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°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 · 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) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

48 / 100
46 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
53%

Weldability

72 / 100
78 / 100

Formability (cold)

62 / 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-HR vs A656 Grade 80 TMCP — frequently asked

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

A656 Grade 80-HR and A656 Grade 80 TMCP are two conditions of the same steel grade, A656 Grade 80: HR (hot rolled) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 590 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus thermomechanically controlled processed).

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

HR is the default A656 Grade 80 condition in the FabDigit quote flow. 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, A656 Grade 80-HR or A656 Grade 80 TMCP?

A656 Grade 80 TMCP. Its weldability rates very good (78/100) against very good (72/100) for A656 Grade 80-HR.

Ready to make it?

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