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Precious Metal S990-H01 vs S990-O

Precious Metal · S990 temper comparison

S990-H01 and S990-O are two conditions of the same precious metal grade, S990: H01 (quarter hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. S990-H01 is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 50 MPa (7.25 ksi) for S990-O, about 3.0 times as much; tensile strength follows at 200 MPa (29 ksi) vs 150 MPa (21.8 ksi). In exchange, S990-O is the more ductile: elongation 45% versus 20% for S990-H01, and S990-H01 is harder (52 HB vs 30 HB). S990-O runs hotter in service (400°C vs 200°C continuous).

S990-H01Choose it when strength drives the design.

S990-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

S990-H01 vs S990-O: properties

S990-H01S990-O

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

200 MPa29 ksi
150 MPa21.8 ksi

Yield Strength (0.2% offset)

150 MPa21.8 ksi
50 MPa7.3 ksi

Elongation at Break

20%
45%

Reduction in Area

55%
80%

Shear Strength

140 MPa20.3 ksi
110 MPa16 ksi

Fatigue Strength (Endurance Limit)

75 MPa10.9 ksi
55 MPa8 ksi

Hardness, Brinell

52 HB
30 HB

Hardness, Vickers

55 HV
32 HV

Same in both: Elastic (Young's) Modulus 78 GPa11.3 Msi · Shear Modulus 29 GPa4.2 Msi · Bulk Modulus 101 GPa14.6 Msi · Poisson's Ratio 0.37

Physical

Density and transition temperatures.

Same in both: Density 10.48 g/cm³0.38 lb/in³ · Melting Point (Solidus) 940°C1,724 °F · Liquidus Temperature 957°C1,755 °F

Thermal

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

Thermal Conductivity

400 W/m·K231 BTU/hr·ft·°F
405 W/m·K234 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Same in both: Specific Heat Capacity 235 J/kg·K0.06 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 19.6 µm/m·K10.9 µin/in·°F · Latent Heat of Fusion 105 J/g45.1 BTU/lb · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

96 % IACS
97 % IACS

Electrical Resistivity

1.8×10⁻⁸ Ω·m0.709 µΩ·in
1.78×10⁻⁸ Ω·m0.701 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 80 / 100

Manufacturability

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

Machinability

58 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
60%

Weldability

55 / 100
60 / 100

Formability (cold)

80 / 100
98 / 100

Same in both: Castability 80 / 100 · Brazeability / Solderability 95 / 100 · Polishability 96 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 1,500 MJ/kg644,885 BTU/lb · Embodied Carbon (primary production) 110 kg CO₂/kg · Embodied Water 8,000 L/kg959 gal/lb · Typical Recycled Content 30%

Strength versus weight

Yield strength against density for every precious metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

50100200500101520Density (g/cm³)Yield strength (MPa) — log scaleS990

S990-H01 vs S990-O — frequently asked

Is S990-H01 stronger than S990-O?

Yes. S990-H01 has a typical yield strength of 150 MPa (21.8 ksi) against 50 MPa (7.25 ksi) for S990-O — about 3.0 times as much. Tensile strength is 200 MPa (29 ksi) vs 150 MPa (21.8 ksi).

Which condition does FabDigit quote by default, H01 or O?

O is the default S990 condition in the FabDigit quote flow. 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, S990-H01 or S990-O?

S990-H01. Its machinability rates good (58/100) against fair (50/100) for S990-O; for welding the order is S990-O first (good, 60/100) then S990-H01 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in S990-H01 and S990-O 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.