Steel AHSS-HR vs AHSS TMCP
Steel · AHSS temper comparison
AHSS-HR and AHSS TMCP are two conditions of the same steel grade, AHSS: HR (hot rolled) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. AHSS TMCP is the stronger of the two: yield strength 460 MPa (66.7 ksi) against 400 MPa (58 ksi) for AHSS-HR, about 15% more. AHSS TMCP is harder — 195 HB against 185 HB for AHSS-HR — which matters for wear surfaces and threads. AHSS TMCP runs hotter in service (250°C vs 200°C continuous).
AHSS TMCPChoose it when strength drives the design, or when surface hardness matters.
AHSS-HR vs AHSS 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.
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 620 MPa89.9 ksi · Shear Strength 390 MPa56.6 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,500°C2,732 °F · Liquidus Temperature 1,520°C2,768 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Min Service Temperature
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 270 J/g116 BTU/lb
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).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V
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 60 / 100 · Polishability 55 / 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 45 L/kg5.4 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.
AHSS-HR vs AHSS TMCP — frequently asked
Is AHSS TMCP stronger than AHSS-HR?
Yes. AHSS TMCP has a typical yield strength of 460 MPa (66.7 ksi) against 400 MPa (58 ksi) for AHSS-HR — about 15% more. Tensile strength is 620 MPa (89.9 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, HR or TMCP?
HR is the default AHSS 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, AHSS-HR or AHSS TMCP?
AHSS TMCP. Its weldability rates very good (80/100) against very good (72/100) for AHSS-HR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AHSS-HR and AHSS 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.