Steel 10B21 Annealed vs 10B21-HR
Steel · 10B21 temper comparison
10B21 Annealed and 10B21-HR are two conditions of the same steel grade, 10B21: Annealed versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 10B21-HR is the stronger of the two: yield strength 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for 10B21 Annealed, about 16% more; tensile strength follows at 430 MPa (62.4 ksi) vs 400 MPa (58 ksi). In exchange, 10B21 Annealed is the more ductile: elongation 34% versus 30% for 10B21-HR, and 10B21-HR is harder (126 HB vs 111 HB).
10B21 AnnealedChoose it when the part is bent, formed or impact-loaded.
10B21-HRChoose it when strength drives the design.
10B21 Annealed vs 10B21-HR: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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 · Shear Strength 275 MPa39.9 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,465°C2,669 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 51.9 W/m·K30 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10.8 % IACS · Electrical Resistivity 1.6×10⁻⁷ Ω·m6.3 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 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: Brazeability / Solderability 70 / 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) 1.9 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 30%
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.
10B21 Annealed vs 10B21-HR — frequently asked
Is 10B21-HR stronger than 10B21 Annealed?
Yes. 10B21-HR has a typical yield strength of 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for 10B21 Annealed — about 16% more. Tensile strength is 430 MPa (62.4 ksi) vs 400 MPa (58 ksi).
Which condition does FabDigit quote by default, Annealed or HR?
HR is the default 10B21 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 is easier to machine, 10B21 Annealed or 10B21-HR?
10B21-HR, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 10B21 Annealed.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 10B21 Annealed and 10B21-HR 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.