PN AlZn6Mg2Cu, CSN 424222, BS 7075 L95 L96 Plates & Sheets

Product Description

The designations PN AlZn6Mg2Cu, CSN 424222, and BS L95 / L96 are regional and industrial equivalents for 7075 Aluminium. These standards specify high-strength aerospace and military grade alloys, primarily used for structural components where extreme mechanical performance is required.

1. Key Equivalents Table

2. Breakdown of the British Standards (L95 & L96)

In British aerospace standards, the specific form of the material dictates the number:

• BS L95: Specifically refers to 7075 Aluminium Plate (typically in T651 temper). It is stress-relieved by stretching to prevent distortion during heavy machining.

• BS L96: Specifically refers to 7075 Aluminium Sheet and Strip (typically in T6 temper). These are thinner gauges used for aircraft skins and structural panels.

3. Chemical Composition (Typical %)

These alloys contain a high percentage of Zinc, which is the primary source of their exceptional strength.

• Zinc (Zn): 5.10 “ 6.10%

• Magnesium (Mg): 2.10 “ 2.90%

• Copper (Cu): 1.20 “ 2.00%

• Chromium (Cr): 0.18 “ 0.28%

• Iron (Fe): 0.50% max

• Aluminium (Al): Remainder

4. Mechanical Properties (T6 / T651 Temper)

5. Critical Engineering Characteristics

• Fatigue Strength: These alloys have a very high fatigue limit, making them essential for parts under repeated stress (e.g., aircraft wings).

• Machinability: Excellent. They are easy to machine to a fine finish, though they are harder on tools than 6000-series alloys.

• Corrosion Protection: Resistance is relatively low. Parts are almost always anodized, painted, or "clad" (BS L95/L96 can be ordered as Alclad, where the high-strength core is sandwiched between layers of pure, corrosion-resistant aluminium).

• Welding: Not recommended. Thermal welding (MIG/TIG) causes severe strength loss and susceptibility to cracking. Mechanical fastening (riveting/bolting) is the standard joining method.

6. Common Industrial Uses

• Defense: Ordnance industries and high-stress military hardware.

• Aerospace: Main structural frames, bulkheads, and wing spars.

• Automotive/Machining: Precision gears, shafts, and high-performance racing components.