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Precious Metal B685 1/4H vs B685-O

Precious Metal · B685 temper comparison

B685 1/4H and B685-O are two conditions of the same precious metal grade, B685: 1/4H (quarter hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. B685 1/4H is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 200 MPa (29 ksi) for B685-O, about 125% more; tensile strength follows at 620 MPa (89.9 ksi) vs 500 MPa (72.5 ksi). In exchange, B685-O is the more ductile: elongation 30% versus 15% for B685 1/4H, and B685 1/4H is harder (190 HV vs 150 HV). B685-O runs hotter in service (450°C vs 300°C continuous).

B685 1/4HChoose it when strength drives the design.

B685-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

B685 1/4H vs B685-O: properties

B685 1/4HB685-O

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
500 MPa72.5 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
200 MPa29 ksi

Elongation at Break

15%
30%

Fatigue Strength (Endurance Limit)

310 MPa45 ksi
260 MPa37.7 ksi

Hardness, Rockwell B

90 HRB
78 HRB

Hardness, Vickers

190 HV
150 HV

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 · Shear Strength 300 MPa43.5 ksi · Hardness, Brinell 145 HB

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.

Max Service Temperature (continuous)

300°C572 °F
450°C842 °F

Same in both: Thermal Conductivity 22 W/m·K12.7 BTU/hr·ft·°F · 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

4.9 % IACS
5 % IACS

Electrical Resistivity

3.55×10⁻⁷ Ω·m14 µΩ·in
3.5×10⁻⁷ Ω·m13.8 µΩ·in

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.

Formability (cold)

65 / 100
88 / 100

Same in both: Machinability 30 / 100 · Machinability Rating (AISI 1212 = 100 %) 22% · Weldability 62 / 100 · 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.

50100200500101520Density (g/cm³)Yield strength (MPa) — log scaleB685

B685 1/4H vs B685-O — frequently asked

Is B685 1/4H stronger than B685-O?

Yes. B685 1/4H has a typical yield strength of 450 MPa (65.3 ksi) against 200 MPa (29 ksi) for B685-O — about 125% more. Tensile strength is 620 MPa (89.9 ksi) vs 500 MPa (72.5 ksi).

Which condition does FabDigit quote by default, 1/4H 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.

When should I choose B685 1/4H over B685-O?

Pick B685 1/4H when strength drives the design. Pick B685-O when the part is bent, formed or impact-loaded, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in B685 1/4H 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.