Precious Metal 9K-AC vs 9K-H04
Precious Metal · 9K temper comparison
9K-AC and 9K-H04 are two conditions of the same precious metal grade, 9K: AC (spheroidize annealed) versus H04 (full hard). The chemistry is identical, so every difference below comes from the condition. 9K-H04 is the stronger of the two: yield strength 560 MPa (81.2 ksi) against 200 MPa (29 ksi) for 9K-AC, about 180% more; tensile strength follows at 660 MPa (95.7 ksi) vs 330 MPa (47.9 ksi). In exchange, 9K-AC is the more ductile: elongation 18% versus 3% for 9K-H04, and 9K-H04 is harder (198 HB vs 124 HB). 9K-AC runs hotter in service (300°C vs 175°C continuous). On the shop floor, 9K-H04 machines more easily (very good vs good).
9K-ACChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
9K-H04Choose it when strength drives the design, or when the part is machined in volume.
9K-AC vs 9K-H04: 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 34 GPa4.9 Msi · Bulk Modulus 110 GPa16 Msi · Poisson's Ratio 0.35
Physical
Density and transition temperatures.
Same in both: Density 11.3 g/cm³0.41 lb/in³ · Melting Point (Solidus) 880°C1,616 °F · Liquidus Temperature 915°C1,679 °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 270 J/kg·K0.06 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 17.5 µm/m·K9.7 µin/in·°F · Latent Heat of Fusion 125 J/g53.7 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).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) 0.05 V
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 80 / 100 · Brazeability / Solderability 90 / 100 · Polishability 88 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 95,000 MJ/kg4.08×10⁷ BTU/lb · Embodied Carbon (primary production) 6,500 kg CO₂/kg · Embodied Water 95,000 L/kg11,383 gal/lb · Typical Recycled Content 35%
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.
9K-AC vs 9K-H04 — frequently asked
Is 9K-H04 stronger than 9K-AC?
Yes. 9K-H04 has a typical yield strength of 560 MPa (81.2 ksi) against 200 MPa (29 ksi) for 9K-AC — about 180% more. Tensile strength is 660 MPa (95.7 ksi) vs 330 MPa (47.9 ksi).
Which condition does FabDigit quote by default, AC or H04?
ANN is the default 9K condition in the FabDigit quote flow (neither AC nor H04). 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, 9K-AC or 9K-H04?
9K-H04. Its machinability rates very good (72/100) against good (60/100) for 9K-AC; for welding the order is 9K-AC first (very good, 70/100) then 9K-H04 (good, 65/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 9K-AC and 9K-H04 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.