Steel A369 FP21-ANN vs A369 FP21 Q&T
Steel · A369 FP21 temper comparison
A369 FP21-ANN and A369 FP21 Q&T are two conditions of the same steel grade, A369 FP21: ANN (annealed) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A369 FP21 Q&T is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 260 MPa (37.7 ksi) for A369 FP21-ANN, about 73% more; tensile strength follows at 620 MPa (89.9 ksi) vs 480 MPa (69.6 ksi). In exchange, A369 FP21-ANN is the more ductile: elongation 32% versus 22% for A369 FP21 Q&T, and A369 FP21 Q&T is harder (210 HB vs 150 HB). On the shop floor, A369 FP21-ANN machines more easily (good vs fair).
A369 FP21-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
A369 FP21 Q&TChoose it when strength drives the design.
A369 FP21-ANN vs A369 FP21 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Compressive Strength 320 MPa46.4 ksi · Shear Strength 340 MPa49.3 ksi · Fracture Toughness (K_IC) 140 MPa·√m127 ksi·√in · Hardness, Rockwell B 88 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 37 W/m·K21.4 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.5 % IACS · Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 20 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 55 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.4 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.
A369 FP21-ANN vs A369 FP21 Q&T — frequently asked
Is A369 FP21 Q&T stronger than A369 FP21-ANN?
Yes. A369 FP21 Q&T has a typical yield strength of 450 MPa (65.3 ksi) against 260 MPa (37.7 ksi) for A369 FP21-ANN — about 73% more. Tensile strength is 620 MPa (89.9 ksi) vs 480 MPa (69.6 ksi).
Which condition does FabDigit quote by default, ANN or Q&T?
N+T is the default A369 FP21 condition in the FabDigit quote flow (neither ANN 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, A369 FP21-ANN or A369 FP21 Q&T?
A369 FP21-ANN. Its machinability rates good (62/100) against fair (45/100) for A369 FP21 Q&T.
Ready to make it?
Upload a CAD file and FabDigit prices the part in A369 FP21-ANN and A369 FP21 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.