Precious Metal S990-H04 vs S990-O
Precious Metal · S990 temper comparison
S990-H04 and S990-O are two conditions of the same precious metal grade, S990: H04 (full hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. S990-H04 is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 50 MPa (7.25 ksi) for S990-O, about 5.0 times as much; tensile strength follows at 290 MPa (42.1 ksi) vs 150 MPa (21.8 ksi). In exchange, S990-O is the more ductile: elongation 45% versus 4% for S990-H04, and S990-H04 is harder (82 HB vs 30 HB). S990-O runs hotter in service (400°C vs 150°C continuous). On the shop floor, S990-H04 machines more easily (good vs fair).
S990-H04Choose it when strength drives the design, or when the part is machined in volume.
S990-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
S990-H04 vs S990-O: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all precious metal grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all precious metal grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
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 · Reduction in Area 80%
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
Max Service Temperature (continuous)
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
Same in both: Electrical Resistivity 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
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 60% · Weldability 60 / 100 · 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.
S990-H04 vs S990-O — frequently asked
Is S990-H04 stronger than S990-O?
Yes. S990-H04 has a typical yield strength of 250 MPa (36.3 ksi) against 50 MPa (7.25 ksi) for S990-O — about 5.0 times as much. Tensile strength is 290 MPa (42.1 ksi) vs 150 MPa (21.8 ksi).
Which condition does FabDigit quote by default, H04 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-H04 or S990-O?
S990-H04. Its machinability rates good (65/100) against fair (50/100) for S990-O.
Ready to make it?
Upload a CAD file and FabDigit prices the part in S990-H04 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.