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Steel A572 Gr 42 vs SPHC

Steel · grade comparison

Steel A572 Gr 42 and SPHC are both steel grades, both structural steel. A572 Gr 42 is the stronger of the two: yield strength 320 MPa (46.4 ksi) against 240 MPa (34.8 ksi) for SPHC, about 33% more; tensile strength follows at 460 MPa (66.7 ksi) vs 310 MPa (45 ksi). In exchange, SPHC is the more ductile: elongation 38% versus 26% for A572 Gr 42, and A572 Gr 42 is harder (140 HB vs 110 HB). On the shop floor, SPHC machines more easily (68 vs 58 out of 100) and SPHC welds better (95 vs 85 out of 100).

A572 Gr 42Choose it when strength drives the design.

SPHCChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

A572 Gr 42 vs SPHC: properties

A572 Gr 42SPHC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
205 GPa29.7 Msi

Shear Modulus

77 GPa11.2 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

460 MPa66.7 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
240 MPa34.8 ksi

Elongation at Break

26%
38%

Reduction in Area

50%
60%

Compressive Strength

320 MPa46.4 ksi
—

Shear Strength

275 MPa39.9 ksi
210 MPa30.5 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
155 MPa22.5 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
120 MPa·√m109 ksi·√in

Hardness, Brinell

140 HB
110 HB

Hardness, Rockwell B

76 HRB
64 HRB

Hardness, Vickers

147 HV
115 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,460°C2,660 °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

48 W/m·K27.7 BTU/hr·ft·°F
52 W/m·K30 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 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

Latent Heat of Fusion

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

Same in both: Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
10.5 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
1.65×10⁻⁷ Ω·m6.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.62 V

Corrosion Resistance

12 / 100
10 / 100

Manufacturability

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

Machinability

58 / 100
68 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
68%

Weldability

85 / 100
95 / 100

Formability (cold)

65 / 100
80 / 100

Brazeability / Solderability

55 / 100
70 / 100

Same in both: Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

40%
25%

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

59 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

256 kJ/m³
140 kJ/m³

Thermal Diffusivity

13 mm²/s
13.8 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 scaleSPHCA572 Gr 42

Manufacturing and finishing

CapabilityA572 Gr 42SPHC
CNC machiningYes—
Default conditionHRHR
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

A572 Gr 42 vs SPHC — frequently asked

Is A572 Gr 42 stronger than SPHC?

Yes. A572 Gr 42 has a typical yield strength of 320 MPa (46.4 ksi) against 240 MPa (34.8 ksi) for SPHC — about 33% more. Tensile strength is 460 MPa (66.7 ksi) vs 310 MPa (45 ksi).

Which is cheaper, A572 Gr 42 or SPHC?

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, A572 Gr 42 or SPHC?

SPHC, by a small margin. Both rate good for machinability — 68/100 against 58/100 for A572 Gr 42; for welding the order is SPHC first (excellent, 95/100) then A572 Gr 42 (excellent, 85/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A572 Gr 42 and SPHC 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.