Al-Si-Cu Casting Alloy

319 (AlSi6Cu3)

The most produced alloy in North America for automotive engine blocks and cylinder heads. Excellent machinability and elevated-temperature strength.

235–250 MPa UTS
5.5–6.5% Silicon (Si)
3.0–4.0% Copper (Cu)

The 319 family (AlSi6Cu3) is the most widely used alloy in North America for engine blocks and cylinder heads. The combination of silicon (~6%) and copper (~3.5%) provides excellent fluidity, good elevated-temperature strength, and outstanding machinability. The B319 variant includes magnesium (0.10–0.50%) for improved T6 heat treatment response. Can be produced from recycled wheel aluminum by adjusting copper content.

International Nomenclature

Standard Designation
AA (USA) 319.0 / B319.0
EN (Europa) EN AC-46200 · AlSi5Cu3Mg
DIN (Alemania) G-AlSi6Cu4 / 3.2151
JIS (Japón) AC2B

Chemical Composition

ElementSymbolPercentage
Aluminum Al Balance
Silicon Si 5.5–6.5%
Copper Cu 3.0–4.0%
Iron Fe ≤1.00% (319) · ≤0.60% (B319)
Magnesium Mg ≤0.10% (319) · 0.10–0.50% (B319)
Manganese Mn ≤0.50%
Zinc Zn ≤1.00%
Nickel Ni ≤0.35%
Titanium Ti ≤0.25%

Physical Properties

Property Value
Density 2.79 g/cm³
Melting Range 520–600 °C
Thermal Conductivity 109 W/m·K
Electrical Conductivity ~27% IACS

Mechanical Properties

Property Value
Tensile Strength (UTS) 235–250 MPa (T6 (B319))
Yield Strength 165–200 MPa (T6)
Elongation 1.5–3.0%
Hardness ~85 HB
Elevated Temp. Strength Retiene resistencia a 200°C+

Key Characteristics

  • The most produced casting alloy in North America for engine blocks
  • Copper provides excellent strength retention at elevated temperatures
  • Outstanding machinability thanks to the Al₂Cu phase
  • B319 with Mg (0.10–0.50%) for improved T6 properties
  • Manufacturable from recycled aluminum wheel base by adjusting Cu content
  • Excellent for permanent mold and sand casting with good pressure tightness

Industries & Applications

Automotive — Powertrain

Engine blocks, cylinder heads, intake manifolds, oil pans

Automotive — Transmission

Transmission housings, transfer cases, valve bodies

Industrial

Compressors, pumps, hydraulic manifolds, valve bodies

Special Notes

319/B319 is the standard GM and Ford alloy for engine blocks and cylinder heads. Its copper content gives it elevated-temperature strength retention (critical for engine components operating at 150–250°C). The B319 variant adds Mg to improve T6 heat treatment response. We can manufacture this alloy starting from recycled wheel aluminum (base ~AlSi7) by adjusting silicon composition and adding copper.

Need 319 (AlSi6Cu3)?

We manufacture this alloy in ingots, donuts, and bars to your exact specifications.

Legal disclaimer: The technical information, chemical compositions, mechanical and physical properties presented on this website are for illustrative and reference purposes only. Actual values may vary depending on manufacturing conditions, heat treatment, and customer process. Transformación Puebla does not guarantee that the data shown here corresponds exactly to the specifications of a particular batch. For guaranteed specifications, please request the technical data sheet and analysis certificate corresponding to your order.