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Steel 55Cr3 vs TDSiCr

Steel · grade comparison

Steel 55Cr3 and TDSiCr are both steel grades. TDSiCr is the stronger of the two: yield strength 1,830 MPa (265 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 3.8 times as much; tensile strength follows at 2,060 MPa (299 ksi) vs 800 MPa (116 ksi). In exchange, 55Cr3 is the more ductile: elongation 16% versus 6% for TDSiCr, and TDSiCr is harder (595 HB vs 225 HB). 55Cr3 runs hotter in service (400°C vs 200°C continuous) and 55Cr3 conducts electricity better (7.8 % IACS vs 5.7 % IACS). On the shop floor, 55Cr3 machines more easily (fair vs not recommended) and 55Cr3 welds better (poor vs not recommended).

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

TDSiCrChoose it when strength drives the design.

55Cr3 vs TDSiCr: properties

55Cr3TDSiCr

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
2,060 MPa299 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
1,830 MPa265 ksi

Elongation at Break

16%
6%

Reduction in Area

40%
50%

Compressive Strength

480 MPa69.6 ksi
2,100 MPa305 ksi

Shear Strength

500 MPa72.5 ksi
1,240 MPa180 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
780 MPa113 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
40 MPa·√m36.4 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
—

Hardness, Brinell

225 HB
595 HB

Hardness, Rockwell B

98 HRB
—

Hardness, Rockwell C

20 HRC
55 HRC

Hardness, Vickers

236 HV
620 HV

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79.5 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.81 g/cm³0.28 lb/in³

Same in both: Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
5.7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
3×10⁻⁷ Ω·m11.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
12 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.6 V

Manufacturability

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

Machinability

50 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
20%

Weldability

25 / 100
10 / 100

Formability (cold)

45 / 100
35 / 100

Brazeability / Solderability

40 / 100
20 / 100

Polishability

60 / 100
55 / 100

Castability

—
0 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.4 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

102 kN·m/kg
264 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

559 kJ/m³
8,128 kJ/m³

Thermal Diffusivity

12.1 mm²/s
11.3 mm²/s

Thermal Shock Resistance Index

14
35

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 scale55Cr3TDSiCr

Manufacturing and finishing

Capability55Cr3TDSiCr
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

55Cr3 vs TDSiCr — frequently asked

Is TDSiCr stronger than 55Cr3?

Yes. TDSiCr has a typical yield strength of 1,830 MPa (265 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 3.8 times as much. Tensile strength is 2,060 MPa (299 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 55Cr3 or TDSiCr?

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, 55Cr3 or TDSiCr?

55Cr3. Its machinability rates fair (50/100) against not recommended (10/100) for TDSiCr; for welding the order is 55Cr3 first (poor, 25/100) then TDSiCr (not recommended, 10/100).

Ready to make it?

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