Steel O2 H&T 54-56 HRC vs O2 Hardened & Tempered
Steel · O2 temper comparison
O2 H&T 54-56 HRC and O2 Hardened & Tempered are two conditions of the same steel grade, O2: H&T 54-56 HRC (hardened & Tempered 54–56 HRC) versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. O2 Hardened & Tempered is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 1,600 MPa (232 ksi) for O2 H&T 54-56 HRC, about 19% more; tensile strength follows at 2,200 MPa (319 ksi) vs 1,850 MPa (268 ksi). In exchange, O2 H&T 54-56 HRC is the more ductile: elongation 3% versus 1% for O2 Hardened & Tempered, and O2 H&T 54-56 HRC is harder (560 HB vs 205 HB). O2 H&T 54-56 HRC runs hotter in service (300°C vs 180°C continuous) and O2 Hardened & Tempered conducts electricity better (8 % IACS vs 6.6 % IACS). On the shop floor, O2 Hardened & Tempered welds better (poor vs not recommended).
O2 H&T 54-56 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
O2 Hardened & TemperedChoose it when strength drives the design, or when it will be welded.
O2 H&T 54-56 HRC vs O2 Hardened & Tempered: 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.
O2 H&T 54-56 HRCO2 Hardened & Tempered
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, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 94 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,460°C2,660 °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) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Same in both: Brazeability / Solderability 35 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 35%
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.
O2 H&T 54-56 HRC vs O2 Hardened & Tempered — frequently asked
Is O2 Hardened & Tempered stronger than O2 H&T 54-56 HRC?
Yes. O2 Hardened & Tempered has a typical yield strength of 1,900 MPa (276 ksi) against 1,600 MPa (232 ksi) for O2 H&T 54-56 HRC — about 19% more. Tensile strength is 2,200 MPa (319 ksi) vs 1,850 MPa (268 ksi).
Which condition does FabDigit quote by default, H&T 54-56 HRC or Hardened & Tempered?
Annealed is the default O2 condition in the FabDigit quote flow (neither H&T 54-56 HRC nor Hardened & Tempered). 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, O2 H&T 54-56 HRC or O2 Hardened & Tempered?
O2 H&T 54-56 HRC, by a small margin. Both rate not recommended for machinability — 10/100 against 5/100 for O2 Hardened & Tempered; for welding the order is O2 Hardened & Tempered first (poor, 15/100) then O2 H&T 54-56 HRC (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in O2 H&T 54-56 HRC and O2 Hardened & Tempered 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.