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Steel 56Si7 +AR vs 56Si7 +H

Steel · 56Si7 temper comparison

56Si7 +AR and 56Si7 +H are two conditions of the same steel grade, 56Si7: +AR (hot rolled) versus +H (treated to a specified hardenability band). The chemistry is identical, so every difference below comes from the condition. 56Si7 +AR is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 520 MPa (75.4 ksi) for 56Si7 +H, about 10% more; tensile strength follows at 1,000 MPa (145 ksi) vs 900 MPa (131 ksi). In exchange, 56Si7 +H is the more ductile: elongation 14% versus 12% for 56Si7 +AR, and 56Si7 +AR is harder (285 HB vs 255 HB). 56Si7 +H runs hotter in service (300°C vs 250°C continuous).

56Si7 +ARChoose it when strength drives the design.

56Si7 +HChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

56Si7 +AR vs 56Si7 +H: properties

56Si7 +AR56Si7 +H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,000 MPa145 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

570 MPa82.7 ksi
520 MPa75.4 ksi

Elongation at Break

12%
14%

Reduction in Area

32%
38%

Compressive Strength

1,050 MPa152 ksi
940 MPa136 ksi

Shear Strength

600 MPa87 ksi
540 MPa78.3 ksi

Fatigue Strength (Endurance Limit)

440 MPa63.8 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

58 MPa·√m52.8 ksi·√in
65 MPa·√m59.2 ksi·√in

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

285 HB
255 HB

Hardness, Rockwell C

29 HRC
25 HRC

Hardness, Vickers

300 HV
268 HV

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
43 W/m·K24.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

250°C482 °F
300°C572 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5.8 % IACS
5.9 % IACS

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 µΩ·in
2.95×10⁻⁷ Ω·m11.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

34 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
42%

Weldability

15 / 100
20 / 100

Formability (cold)

25 / 100
30 / 100

Same in both: Brazeability / Solderability 35 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 28 MJ/kg12,038 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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 scale56Si7

56Si7 +AR vs 56Si7 +H — frequently asked

Is 56Si7 +AR stronger than 56Si7 +H?

Yes. 56Si7 +AR has a typical yield strength of 570 MPa (82.7 ksi) against 520 MPa (75.4 ksi) for 56Si7 +H — about 10% more. Tensile strength is 1,000 MPa (145 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, +AR or +H?

+QT is the default 56Si7 condition in the FabDigit quote flow (neither +AR nor +H). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which welds better, 56Si7 +AR or 56Si7 +H?

56Si7 +H. Its weldability rates poor (20/100) against poor (15/100) for 56Si7 +AR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 56Si7 +AR and 56Si7 +H 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.