Steel P92 vs Q345R
Steel · grade comparison
Steel P92 and Q345R are both steel grades, both pressure vessel steel. P92 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 370 MPa (53.7 ksi) for Q345R, about 68% more; tensile strength follows at 850 MPa (123 ksi) vs 550 MPa (79.8 ksi). In exchange, Q345R is the more ductile: elongation 24% versus 17% for P92, and P92 is harder (280 HB vs 160 HB). Q345R conducts heat better (48 W/m·K vs 27 W/m·K). On the shop floor, Q345R machines more easily (good vs poor) and Q345R welds better (excellent vs poor).
P92Choose it when strength drives the design.
Q345RChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
P92 vs Q345R: 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Hardness, Rockwell B
Same in both: Poisson's Ratio 0.29 · Reduction in Area 50%
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Galvanic Potential (seawater, vs SCE)
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | P92 | Q345R |
|---|---|---|
| Default condition | HR | HR |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.
P92 vs Q345R — frequently asked
Is P92 stronger than Q345R?
Yes. P92 has a typical yield strength of 620 MPa (89.9 ksi) against 370 MPa (53.7 ksi) for Q345R — about 68% more. Tensile strength is 850 MPa (123 ksi) vs 550 MPa (79.8 ksi).
Which is cheaper, P92 or Q345R?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, P92 or Q345R?
Q345R. Its machinability rates good (62/100) against poor (28/100) for P92; for welding the order is Q345R first (excellent, 85/100) then P92 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in P92 and Q345R 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.