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Steel A570 vs SPHD

Steel · grade comparison

Steel A570 and SPHD are both steel grades. A570 is the stronger of the two: yield strength 285 MPa (41.3 ksi) against 230 MPa (33.4 ksi) for SPHD, about 24% more; tensile strength follows at 400 MPa (58 ksi) vs 320 MPa (46.4 ksi). In exchange, SPHD is the more ductile: elongation 37% versus 22% for A570, and A570 is harder (120 HB vs 100 HB). A570 runs hotter in service (400°C vs 350°C continuous).

A570Choose it when strength drives the design, or when the part sees heat.

SPHDChoose it when the part is bent, formed or impact-loaded.

A570 vs SPHD: properties

A570SPHD

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Shear Modulus

79 GPa11.5 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

400 MPa58 ksi
320 MPa46.4 ksi

Yield Strength (0.2% offset)

285 MPa41.3 ksi
230 MPa33.4 ksi

Elongation at Break

22%
37%

Reduction in Area

55%
65%

Shear Strength

260 MPa37.7 ksi
205 MPa29.7 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
155 MPa22.5 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

120 HB
100 HB

Hardness, Rockwell B

70 HRB
55 HRB

Compressive Strength

—
230 MPa33.4 ksi

Hardness, Vickers

—
105 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,495°C2,723 °F

Liquidus Temperature

1,510°C2,750 °F
1,530°C2,786 °F

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

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

Specific Heat Capacity

486 J/kg·K0.12 BTU/lb·°F
480 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Same in both: Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 10.8 % IACS · 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

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Formability (cold)

70 / 100
90 / 100

Same in both: Weldability 92 / 100 · Brazeability / Solderability 70 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2 kg CO₂/kg
2.2 kg CO₂/kg

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

51 kN·m/kg
41 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

203 kJ/m³
129 kJ/m³

Thermal Diffusivity

13.6 mm²/s
13.5 mm²/s

Thermal Shock Resistance Index

9
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 scaleSPHDA570

Manufacturing and finishing

CapabilityA570SPHD
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.

A570 vs SPHD — frequently asked

Is A570 stronger than SPHD?

Yes. A570 has a typical yield strength of 285 MPa (41.3 ksi) against 230 MPa (33.4 ksi) for SPHD — about 24% more. Tensile strength is 400 MPa (58 ksi) vs 320 MPa (46.4 ksi).

Which is cheaper, A570 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.

Which is easier to machine, A570 or SPHD?

A570, by a small margin. Both rate good for machinability — 60/100 against 55/100 for SPHD.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A570 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.