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Steel A242 vs SM570

Steel · grade comparison

Steel A242 and SM570 are both steel grades. SM570 is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 370 MPa (53.7 ksi) for A242, about 32% more; tensile strength follows at 630 MPa (91.4 ksi) vs 510 MPa (74 ksi). SM570 is harder — 190 HB against 155 HB for A242 — which matters for wear surfaces and threads. On the shop floor, A242 forms better (65 vs 55 out of 100).

SM570Choose it when strength drives the design, or when surface hardness matters.

A242 vs SM570: properties

A242SM570

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

510 MPa74 ksi
630 MPa91.4 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
490 MPa71.1 ksi

Reduction in Area

50%
55%

Compressive Strength

370 MPa53.7 ksi
490 MPa71.1 ksi

Shear Strength

320 MPa46.4 ksi
390 MPa56.6 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
285 MPa41.3 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
125 MPa·√m114 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
95 J70.1 ft·lbf

Hardness, Brinell

155 HB
190 HB

Hardness, Rockwell B

82 HRB
92 HRB

Hardness, Vickers

163 HV
200 HV

Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 24%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,425°C2,597 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°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

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 350°C662 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8.6 % IACS

Same in both: Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.65 V

Corrosion Resistance

35 / 100
12 / 100

Manufacturability

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

Machinability

58 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

80 / 100
72 / 100

Formability (cold)

65 / 100
55 / 100

Brazeability / Solderability

40 / 100
55 / 100

Same in both: Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
27 MJ/kg11,608 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Typical Recycled Content

30%
25%

Same in both: Embodied Water 40 L/kg4.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
80 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

342 kJ/m³
583 kJ/m³

Thermal Diffusivity

13 mm²/s
12.2 mm²/s

Thermal Shock Resistance Index

10
11

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 scaleA242SM570

Manufacturing and finishing

CapabilityA242SM570
Default condition——
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

A242 vs SM570 — frequently asked

Is SM570 stronger than A242?

Yes. SM570 has a typical yield strength of 490 MPa (71.1 ksi) against 370 MPa (53.7 ksi) for A242 — about 32% more. Tensile strength is 630 MPa (91.4 ksi) vs 510 MPa (74 ksi).

Which is cheaper, A242 or SM570?

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, A242 or SM570?

A242. Its machinability rates good (58/100) against fair (52/100) for SM570; for welding the order is A242 first (very good, 80/100) then SM570 (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A242 and SM570 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.