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Steel 56Si7 +H vs 56Si7 +S

Steel · 56Si7 temper comparison

56Si7 +H and 56Si7 +S are two conditions of the same steel grade, 56Si7: +H (treated to a specified hardenability band) versus +S (treated for high shearability). The chemistry is identical, so every difference below comes from the condition. 56Si7 +H is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 440 MPa (63.8 ksi) for 56Si7 +S, about 18% more; tensile strength follows at 900 MPa (131 ksi) vs 760 MPa (110 ksi). In exchange, 56Si7 +S is the more ductile: elongation 18% versus 14% for 56Si7 +H, and 56Si7 +H is harder (255 HB vs 215 HB).

56Si7 +HChoose it when strength drives the design.

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

56Si7 +H vs 56Si7 +S: properties

56Si7 +H56Si7 +S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
440 MPa63.8 ksi

Elongation at Break

14%
18%

Reduction in Area

38%
45%

Compressive Strength

940 MPa136 ksi
780 MPa113 ksi

Shear Strength

540 MPa78.3 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
340 MPa49.3 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
28 J20.7 ft·lbf

Hardness, Brinell

255 HB
215 HB

Hardness, Rockwell C

25 HRC
17 HRC

Hardness, Vickers

268 HV
225 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

43 W/m·K24.8 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°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 · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5.9 % IACS
6 % IACS

Electrical Resistivity

2.95×10⁻⁷ Ω·m11.6 µΩ·in
2.9×10⁻⁷ Ω·m11.4 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

38 / 100
46 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
52%

Weldability

20 / 100
25 / 100

Formability (cold)

30 / 100
45 / 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 +H vs 56Si7 +S — frequently asked

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

Yes. 56Si7 +H has a typical yield strength of 520 MPa (75.4 ksi) against 440 MPa (63.8 ksi) for 56Si7 +S — about 18% more. Tensile strength is 900 MPa (131 ksi) vs 760 MPa (110 ksi).

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

+QT is the default 56Si7 condition in the FabDigit quote flow (neither +H nor +S). 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 is easier to machine, 56Si7 +H or 56Si7 +S?

56Si7 +S, by a small margin. Both rate fair for machinability — 46/100 against 38/100 for 56Si7 +H; for welding the order is 56Si7 +S first (poor, 25/100) then 56Si7 +H (poor, 20/100).

Ready to make it?

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