Birmabright is a trade name of the former Birmetals Co. (Birmabright works in Clapgate Lane, Quinton,

Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands, within the wider West Midlands (region), West Midlands region, in England. It is the Lis ...

, UK) for various types of lightweight sheet metal in an aluminium–magnesium alloy. The alloy was introduced by the Birmid Group in 1929 and was particularly noted for its corrosion resistance. Birmal Boats was created in 1930 for the building of light-alloy boats. Birmetals Ltd was formed in 1936 and during the war produced both copper bearing aluminium alloys and the Birmabright magnesium bearing alloys, mainly for aircraft production. The constituents were from 1% to 7% magnesium, with <1%

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

, and the remainder aluminium. The alloys were provided in different temper conditions. e.g. soft, 1/4 hard, 1/2 hard and were designed to be work hardened e.g. by cold pressing into shape. They do not exhibit age hardening, or have a precipitation heat treatment to promote hardening (unlike other contemporary aluminium alloys such as

Duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' ...

). Weldability is good but machinability is only fair to poor. The alloy has good seawater corrosion resistance (unlike

). Birmetals Ltd Birmabright grades included the following : Woldman's Engineering Alloys, John P Frick, ASM International, Jan 2000. The Birmabright designations are obsolete, but equivalent grades exist, for example BB2 equivalent specifications are British standard NS4, American 5251 and

ISO The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. Me ...

designation AlMg2.

Gas welding Principle of burn cutting Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding in the United States) and oxy-fuel cutting are processes that use fuel gases (or liquid fuels such as gasoline or petrol, diesel, bio ...

of Birmabright is easier than that of pure aluminium and may be carried out autogenously using scraps of the same material as a filler rod. Birmabright is best known as the material used in the body of the

Land Rover Land Rover is a brand of predominantly four-wheel drive, off-road capable vehicles, owned by British multinational car manufacturer Jaguar Land Rover (JLR), since 2008 a subsidiary of India's Tata Motors. JLR builds Land Rovers in Brazil ...

from its launch in April 1948, and in a few other classic British vehicles. The doors, boot lid and bonnet of most

Rover P4 The Rover P4 series is a group of mid-size luxury saloon cars produced by the Rover Company from 1949 until 1964. They were designed by Gordon Bashford. The P4 designation is factory terminology for this group of cars and was not in day-to-d ...

models were also Birmabright, however towards the end of production this was changed to steel to reduce costs. An early use in the 1930s was for the bodywork of the

land speed record The land speed record (LSR) or absolute land speed record is the highest speed achieved by a person using a vehicle on land. By a 1964 agreement between the Fédération Internationale de l'Automobile (FIA) and Fédération Internationale de M ...

car,

Thunderbolt A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the 'Sky Father'; this association is also found in later Hel ...

. Also used for the bodywork of

Bluebird K7 ''Bluebird K7'' is a jet engined Hydroplane (boat), hydroplane in which Britain's Donald Campbell set seven world water speed records between 1955 and 1967. ''K7'' was the first successful jet-powered hydroplane, and was considered revoluti ...

used for the Coniston speed record attempt by Donald Campbell. The well known

Laurent Giles John Laurent Giles (1901–1969) was an English naval architect who was particularly famous for his sailing yachts. He and his company, Laurent Giles & Partners Ltd, have designed more than 1400 boats from cruisers and racing yachts to megayachts. ...

designed 46ft sailboat ''Beyond'' was built of riveted sheets of Birmabright and circumnavigated in the early 1950s by Tom and Ann Worth. The hull proved corrosion resistant but required re-riveting later due to crystallisation of the rivet heads, and lasted well until being sunk in the Caribbean as an artificial diving reef in the 1980s. Birmetals (part of the Birmid Qualcast Group) closed its factory in 1980 after losing money in 1977-1979, followed by a protracted strike over wages by key staff which prevented production.

References

Aluminium–magnesium alloys Aluminium alloys Aerospace materials Land Rover vehicles {{Alloy-stub

See also

References