Steel P20 Prehard vs P20 Q&T
Steel · P20 temper comparison
P20 Prehard and P20 Q&T are two conditions of the same steel grade, P20: Prehard (pre-hardened) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. P20 Q&T is the stronger of the two: yield strength 1,150 MPa (167 ksi) against 860 MPa (125 ksi) for P20 Prehard, about 34% more; tensile strength follows at 1,350 MPa (196 ksi) vs 1,000 MPa (145 ksi). In exchange, P20 Prehard is the more ductile: elongation 15% versus 11% for P20 Q&T, and P20 Q&T is harder (390 HB vs 300 HB). P20 Prehard runs hotter in service (450°C vs 350°C continuous). On the shop floor, P20 Prehard machines more easily (good vs fair).
P20 PrehardChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
P20 Q&TChoose it when strength drives the design.
P20 Prehard vs P20 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
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 · Compressive Strength 900 MPa131 ksi · Shear Strength 620 MPa89.9 ksi · Hardness, Rockwell B 93 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.8 g/cm³0.28 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 32 W/m·K18.5 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.4 µm/m·K6.9 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 Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 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 %)
Polishability
Same in both: Weldability 50 / 100 · Formability (cold) 30 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
P20 Prehard vs P20 Q&T — frequently asked
Is P20 Q&T stronger than P20 Prehard?
Yes. P20 Q&T has a typical yield strength of 1,150 MPa (167 ksi) against 860 MPa (125 ksi) for P20 Prehard — about 34% more. Tensile strength is 1,350 MPa (196 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, Prehard or Q&T?
Annealed is the default P20 condition in the FabDigit quote flow (neither Prehard 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, P20 Prehard or P20 Q&T?
P20 Prehard. Its machinability rates good (55/100) against fair (35/100) for P20 Q&T.
Ready to make it?
Upload a CAD file and FabDigit prices the part in P20 Prehard and P20 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.