Steel H24-HR vs H24-HT55
Steel · H24 temper comparison
H24-HR and H24-HT55 are two conditions of the same steel grade, H24: HR (hot rolled) versus HT55 (hardened & tempered). The chemistry is identical, so every difference below comes from the condition. H24-HT55 is the stronger of the two: yield strength 1,700 MPa (247 ksi) against 700 MPa (102 ksi) for H24-HR, about 143% more; tensile strength follows at 1,950 MPa (283 ksi) vs 1,000 MPa (145 ksi). In exchange, H24-HR is the more ductile: elongation 10% versus 4% for H24-HT55, and H24-HR is harder (300 HB vs 220 HB). H24-HT55 runs hotter in service (620°C vs 550°C continuous). On the shop floor, H24-HR machines more easily (poor vs not recommended).
H24-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
H24-HT55Choose it when strength drives the design, or when the part sees heat.
H24-HR vs H24-HT55: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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
Physical
Density and transition temperatures.
Same in both: Density 8.55 g/cm³0.31 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 15 / 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: Castability 25 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 42 MJ/kg18,057 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 40%
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.
H24-HR vs H24-HT55 — frequently asked
Is H24-HT55 stronger than H24-HR?
Yes. H24-HT55 has a typical yield strength of 1,700 MPa (247 ksi) against 700 MPa (102 ksi) for H24-HR — about 143% more. Tensile strength is 1,950 MPa (283 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, HR or HT55?
Annealed is the default H24 condition in the FabDigit quote flow (neither HR nor HT55). 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, H24-HR or H24-HT55?
H24-HR. Its machinability rates poor (22/100) against not recommended (5/100) for H24-HT55; for welding the order is H24-HR first (poor, 20/100) then H24-HT55 (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in H24-HR and H24-HT55 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.