Steel 30CrNiMo8 +A vs 30CrNiMo8 Q&T
Steel · 30CrNiMo8 temper comparison
30CrNiMo8 +A and 30CrNiMo8 Q&T are two conditions of the same steel grade, 30CrNiMo8: +A (annealed) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 30CrNiMo8 Q&T is the stronger of the two: yield strength 1,000 MPa (145 ksi) against 520 MPa (75.4 ksi) for 30CrNiMo8 +A, about 92% more; tensile strength follows at 1,200 MPa (174 ksi) vs 780 MPa (113 ksi). In exchange, 30CrNiMo8 +A is the more ductile: elongation 18% versus 12% for 30CrNiMo8 Q&T, and 30CrNiMo8 Q&T is harder (355 HB vs 225 HB). On the shop floor, 30CrNiMo8 +A machines more easily (52 vs 38 out of 100).
30CrNiMo8 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
30CrNiMo8 Q&TChoose it when strength drives the design.
30CrNiMo8 +A vs 30CrNiMo8 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 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 1,050 MPa152 ksi · Shear Strength 720 MPa104 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in · Hardness, Rockwell C 38 HRC
Physical
Density and transition temperatures.
Same in both: Density 7.85 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.
Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -50°C-58 °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: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 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 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 55 L/kg6.6 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.
30CrNiMo8 +A vs 30CrNiMo8 Q&T — frequently asked
Is 30CrNiMo8 Q&T stronger than 30CrNiMo8 +A?
Yes. 30CrNiMo8 Q&T has a typical yield strength of 1,000 MPa (145 ksi) against 520 MPa (75.4 ksi) for 30CrNiMo8 +A — about 92% more. Tensile strength is 1,200 MPa (174 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, +A or Q&T?
Q&T is the default 30CrNiMo8 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, 30CrNiMo8 +A or 30CrNiMo8 Q&T?
30CrNiMo8 +A, by a small margin. Both rate fair for machinability — 52/100 against 38/100 for 30CrNiMo8 Q&T; for welding the order is 30CrNiMo8 +A first (poor, 30/100) then 30CrNiMo8 Q&T (poor, 22/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 30CrNiMo8 +A and 30CrNiMo8 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.