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Steel 28B2 vs 55Cr3

Steel · grade comparison

Steel 28B2 and 55Cr3 are both steel grades. 28B2 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 8% more. In exchange, 55Cr3 is the more ductile: elongation 16% versus 12% for 28B2, and 55Cr3 is harder (225 HB vs 190 HB). 55Cr3 runs hotter in service (400°C vs 350°C continuous) and 28B2 conducts electricity better (9 % IACS vs 7.8 % IACS). On the shop floor, 28B2 welds better (fair vs poor) and 28B2 sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

28B2Choose it when strength drives the design, or when it will be welded.

55Cr3Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

28B2 vs 55Cr3: properties

28B255Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
480 MPa69.6 ksi

Elongation at Break

12%
16%

Reduction in Area

55%
40%

Shear Strength

400 MPa58 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
360 MPa52.2 ksi

Hardness, Brinell

190 HB
225 HB

Hardness, Rockwell B

91 HRB
98 HRB

Compressive Strength

—
480 MPa69.6 ksi

Fracture Toughness (K_IC)

—
85 MPa·√m77.4 ksi·√in

Hardness, Rockwell C

—
20 HRC

Hardness, Vickers

—
236 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 30 J22.1 ft·lbf

Physical

Density and transition temperatures.

Liquidus Temperature

1,500°C2,732 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

47 W/m·K27.2 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
465 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
7.8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
—

Same in both: Corrosion Resistance 10 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability Rating (AISI 1212 = 100 %)

62%
55%

Weldability

45 / 100
25 / 100

Formability (cold)

65 / 100
45 / 100

Brazeability / Solderability

60 / 100
40 / 100

Polishability

55 / 100
60 / 100

Same in both: Machinability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

70 L/kg8.4 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

660 kJ/m³
559 kJ/m³

Thermal Diffusivity

12.7 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

12
14

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale55Cr328B2

Manufacturing and finishing

Capability28B255Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$ Budget$$ Standard
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.

28B2 vs 55Cr3 — frequently asked

Is 28B2 stronger than 55Cr3?

Yes. 28B2 has a typical yield strength of 520 MPa (75.4 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 8% more. Tensile strength is 620 MPa (89.9 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 28B2 or 55Cr3?

28B2 is the lower-cost material: it sits in the budget tier ($) while 55Cr3 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 28B2 or 55Cr3?

28B2. Its weldability rates fair (45/100) against poor (25/100) for 55Cr3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 28B2 and 55Cr3 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.