Strength in numbers

Aluminium Alloy   |   BS-L

2L77 T6


High strength structural components: aircraft (e.g. fittings and wheels), military vehicles and bridges, forgings for trucks and machinery (hydraulic etc.). Weapons manufacture, structural applications.

Characteristic Properties:
Heat treatable alloy. High mechanical strength slightly higher than 2011 and 2017A.

Chemical Composition

BS 2L77(1971)
Alloy 2L77
Chemical Element % Present
Aluminium (Al) balance
Tin (Sn) 0.05 max
Lead (Pb) 0.05 max
Chromium (Cr) 0.1 max
Zinc (Zn) 0.2 max
Titanium + Zirconium (Ti+Zr) 0.2 max
Nickel (Ni) 0.2 max
Iron (Fe) 0.5 max
Magnesium (Mg) 0.2 - 0.8
Silicon (Si) 0.5 - 0.9
Manganese (Mn) 0.4 - 1.2
Copper (Cu) 3.9 - 5

Forging Stock: Cast billets and slabs for hot working and extruded bars, sections and hot-rolled plate for forging shall be supplied non-heat treated. Forgings: Unless otherwise agreed between the manufacturer and the purchaser and stated on the order, forgings shall be supplied solution treated and precipitation treated.

Alloy Designations

Aluminium alloy 2L77 - 2014A is covered by standard BS EN 4L77 (1971)

Temper Types

The most common temper for 2L77 - 2014A aluminium forging stock is:

  • T6

Supplied Forms

2L77 - 2014A aluminium is supplied as forging stock made from cast billet, extruded stock or rolled plate.

  • Forgings
  • Bar
  • Castings
  • Extrusions
  • Plate

Generic Physical Properties

Physical Property Value
Density 2.80 g/cm³
Melting Point 640 °C
Thermal Expansion 22.8 x10^-6 /K
Modulus of Elasticity 73 GPa
Thermal Conductivity 134-155 W/m.K
Solution treat by heating at a temp of 500C +/- 5C and quenching in water at a temperature not less than 40C nor more than 70C, unless otherwise agreed by the parent design firm and the manufacturer. If a water quenching temperature below 40 C is used, high residual stress and cracking may result, particularly in large and / or complicated forgings. For this reason it is desirable to quench in water at as high a temperature as is practible.

Mechanical Properties

BS 2L77(1971)
Mechanical Property Value
Elongation A50 mm 6 Min %
Hardness Brinell 134 Min HB
Proof Stress 395 Min MPa
Tensile Strength 450 Min MPa

This specification covers forging stock and forgings of aluminium-copper-magnesium-silicon-manganese alloy in the solution treated and precipitation treated condition. The values shown in the mechanical properties apply to test pieces prepared by forging covering extruded forging stock and forgings made from cast billets, hot-rolled plate and extruded stock in all sizes.