Steel 10B21 vs 15B48
Steel · grade comparison
Steel 10B21 and 15B48 are both steel grades. 15B48 is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 290 MPa (42.1 ksi) for 10B21, about 33% more; tensile strength follows at 585 MPa (84.8 ksi) vs 430 MPa (62.4 ksi). In exchange, 10B21 is the more ductile: elongation 30% versus 22% for 15B48, and 15B48 is harder (170 HB vs 126 HB). 10B21 conducts heat better (51.9 W/m·K vs 46 W/m·K). On the shop floor, 10B21 welds better (excellent vs fair).
10B21Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
15B48Choose it when strength drives the design.
10B21 vs 15B48: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 65%
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg
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 | 10B21 | 15B48 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | HR | — |
| Relative cost | $ Budget | $ Budget |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
10B21 vs 15B48 — frequently asked
Is 15B48 stronger than 10B21?
Yes. 15B48 has a typical yield strength of 385 MPa (55.8 ksi) against 290 MPa (42.1 ksi) for 10B21 — about 33% more. Tensile strength is 585 MPa (84.8 ksi) vs 430 MPa (62.4 ksi).
Which is cheaper, 10B21 or 15B48?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 10B21 or 15B48?
10B21, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 15B48; for welding the order is 10B21 first (excellent, 85/100) then 15B48 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 10B21 and 15B48 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.