Steel 30MoB1 +C vs 30MoB1 +U
Steel · 30MoB1 temper comparison
30MoB1 +C and 30MoB1 +U are two conditions of the same steel grade, 30MoB1: +C (cold drawn) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 30MoB1 +C is the stronger of the two: yield strength 610 MPa (88.5 ksi) against 410 MPa (59.5 ksi) for 30MoB1 +U, about 49% more; tensile strength follows at 710 MPa (103 ksi) vs 660 MPa (95.7 ksi). In exchange, 30MoB1 +U is the more ductile: elongation 17% versus 8% for 30MoB1 +C, and 30MoB1 +C is harder (210 HB vs 195 HB). 30MoB1 +U runs hotter in service (350°C vs 300°C continuous). On the shop floor, 30MoB1 +C machines more easily (65 vs 55 out of 100).
30MoB1 +CChoose it when strength drives the design, or when the part is machined in volume.
30MoB1 +UChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
30MoB1 +C vs 30MoB1 +U: 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)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 540 MPa78.3 ksi · Shear Strength 380 MPa55.1 ksi · Charpy V-Notch Impact (RT) 55 J40.6 ft·lbf
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,430°C2,606 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8 % IACS · 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) -0.61 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 %)
Formability (cold)
Same in both: Weldability 50 / 100 · Brazeability / Solderability 60 / 100 · Polishability 55 / 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 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.
30MoB1 +C vs 30MoB1 +U — frequently asked
Is 30MoB1 +C stronger than 30MoB1 +U?
Yes. 30MoB1 +C has a typical yield strength of 610 MPa (88.5 ksi) against 410 MPa (59.5 ksi) for 30MoB1 +U — about 49% more. Tensile strength is 710 MPa (103 ksi) vs 660 MPa (95.7 ksi).
Which condition does FabDigit quote by default, +C or +U?
+AC+C is the default 30MoB1 condition in the FabDigit quote flow (neither +C nor +U). 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, 30MoB1 +C or 30MoB1 +U?
30MoB1 +C, by a small margin. Both rate good for machinability — 65/100 against 55/100 for 30MoB1 +U.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 30MoB1 +C and 30MoB1 +U 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.