Steel H21 Hot Rolled vs H21 Q&T
Steel · H21 temper comparison
H21 Hot Rolled and H21 Q&T are two conditions of the same steel grade, H21: Hot Rolled versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. H21 Q&T is the stronger of the two: yield strength 1,450 MPa (210 ksi) against 850 MPa (123 ksi) for H21 Hot Rolled, about 71% more; tensile strength follows at 1,700 MPa (247 ksi) vs 1,100 MPa (160 ksi). In exchange, H21 Hot Rolled is the more ductile: elongation 10% versus 8% for H21 Q&T, and H21 Hot Rolled is harder (320 HB vs 220 HB). H21 Q&T runs hotter in service (600°C vs 500°C continuous). On the shop floor, H21 Hot Rolled machines more easily (25 vs 15 out of 100) and H21 Q&T welds better (fair vs poor).
H21 Hot RolledChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
H21 Q&TChoose it when strength drives the design, or when the part sees heat.
H21 Hot Rolled vs H21 Q&T: 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 97 HRB
Physical
Density and transition temperatures.
Same in both: Density 8.28 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 27 W/m·K15.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 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: 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 30 / 100 · Brazeability / Solderability 40 / 100 · Polishability 65 / 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 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 45%
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.
H21 Hot Rolled vs H21 Q&T — frequently asked
Is H21 Q&T stronger than H21 Hot Rolled?
Yes. H21 Q&T has a typical yield strength of 1,450 MPa (210 ksi) against 850 MPa (123 ksi) for H21 Hot Rolled — about 71% more. Tensile strength is 1,700 MPa (247 ksi) vs 1,100 MPa (160 ksi).
Which condition does FabDigit quote by default, Hot Rolled or Q&T?
Annealed is the default H21 condition in the FabDigit quote flow (neither Hot Rolled nor Q&T). 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, H21 Hot Rolled or H21 Q&T?
H21 Hot Rolled, by a small margin. Both rate poor for machinability — 25/100 against 15/100 for H21 Q&T; for welding the order is H21 Q&T first (fair, 35/100) then H21 Hot Rolled (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in H21 Hot Rolled and H21 Q&T 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.