Precious Metal B685-H vs B685-O
Precious Metal · B685 temper comparison
B685-H and B685-O are two conditions of the same precious metal grade, B685: H (hardened) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. B685-H is the stronger of the two: yield strength 860 MPa (125 ksi) against 200 MPa (29 ksi) for B685-O, about 4.3 times as much; tensile strength follows at 1,000 MPa (145 ksi) vs 500 MPa (72.5 ksi). In exchange, B685-O is the more ductile: elongation 30% versus 2.5% for B685-H, and B685-H is harder (270 HV vs 150 HV). B685-O runs hotter in service (450°C vs 250°C continuous). On the shop floor, B685-H machines more easily (fair vs poor).
B685-HChoose it when strength drives the design, or when the part is machined in volume.
B685-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
B685-H vs B685-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, Vickers
Same in both: Elastic (Young's) Modulus 130 GPa18.9 Msi · Shear Modulus 48 GPa7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.37 · Hardness, Brinell 145 HB · Hardness, Rockwell B 78 HRB
Physical
Density and transition temperatures.
Same in both: Density 10.4 g/cm³0.38 lb/in³ · Melting Point (Solidus) 1,200°C2,192 °F · Liquidus Temperature 1,230°C2,246 °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 300 J/kg·K0.07 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14 µm/m·K7.8 µin/in·°F · Latent Heat of Fusion 176 J/g75.7 BTU/lb · Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) 0.15 V · Corrosion Resistance 92 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 55 / 100 · Brazeability / Solderability 85 / 100 · Polishability 90 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 24,000 MJ/kg1.03×10⁷ BTU/lb · Embodied Carbon (primary production) 2,200 kg CO₂/kg · Embodied Water 90,000 L/kg10,784 gal/lb · Typical Recycled Content 45%
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.
B685-H vs B685-O — frequently asked
Is B685-H stronger than B685-O?
Yes. B685-H has a typical yield strength of 860 MPa (125 ksi) against 200 MPa (29 ksi) for B685-O — about 4.3 times as much. Tensile strength is 1,000 MPa (145 ksi) vs 500 MPa (72.5 ksi).
Which condition does FabDigit quote by default, H or O?
O is the default B685 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, B685-H or B685-O?
B685-H. Its machinability rates fair (45/100) against poor (30/100) for B685-O; for welding the order is B685-O first (good, 62/100) then B685-H (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in B685-H and B685-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.