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Steel DD13 vs SPHD

Steel · grade comparison

Steel DD13 and SPHD are both steel grades. DD13 is the stronger of the two: tensile strength 340 MPa (49.3 ksi) against 320 MPa (46.4 ksi) for SPHD, about 6% more. DD13 is harder — 58 HRB against 55 HRB for SPHD — which matters for wear surfaces and threads.

DD13Choose it when strength drives the design, or when surface hardness matters.

DD13 vs SPHD: properties

DD13SPHD

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

340 MPa49.3 ksi
320 MPa46.4 ksi

Elongation at Break

36%
37%

Shear Strength

230 MPa33.4 ksi
205 MPa29.7 ksi

Fatigue Strength (Endurance Limit)

160 MPa23.2 ksi
155 MPa22.5 ksi

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

105 HB
100 HB

Hardness, Rockwell B

58 HRB
55 HRB

Hardness, Vickers

110 HV
105 HV

Fracture Toughness (K_IC)

—
100 MPa·√m91 ksi·√in

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 230 MPa33.4 ksi · Reduction in Area 65% · Compressive Strength 230 MPa33.4 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,525°C2,777 °F
1,530°C2,786 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

52 W/m·K30 BTU/hr·ft·°F
51 W/m·K29.5 BTU/hr·ft·°F

Specific Heat Capacity

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

Latent Heat of Fusion

270 J/g116 BTU/lb
247 J/g106 BTU/lb

Same in both: Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

11 % IACS
10.8 % IACS

Same in both: Electrical Resistivity 1.6×10⁻⁷ Ω·m6.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-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

58 / 100
55 / 100

Weldability

96 / 100
92 / 100

Brazeability / Solderability

65 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 55% · Formability (cold) 90 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

23 MJ/kg9,888 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

35 L/kg4.2 gal/lb
40 L/kg4.8 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

43 kN·m/kg
41 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

126 kJ/m³
129 kJ/m³

Thermal Diffusivity

14.1 mm²/s
13.5 mm²/s

Same in both: Thermal Shock Resistance Index 7

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 scaleSPHDDD13

Manufacturing and finishing

CapabilityDD13SPHD
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——
Black Oxide—Yes
Cerakote—Yes
Chrome Plating—Yes
E-Coating—Yes
Hot-Dip Galvanizing—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes
Powder Coating—Yes
Tin Plating—Yes
Zinc Plating—Yes
Zinc-Flake (Dip-Spin) Coating—Yes
Zinc-Nickel Plating—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.

DD13 vs SPHD — frequently asked

Is DD13 stronger than SPHD?

Yes. DD13 has a typical tensile strength of 340 MPa (49.3 ksi) against 320 MPa (46.4 ksi) for SPHD — about 6% more.

Which is cheaper, DD13 or SPHD?

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.

When should I choose DD13 over SPHD?

Pick DD13 when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in DD13 and SPHD 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.