This includes blacksmiths, other smiths, including benders, hammermen, stampers and welders, and other skilled and semi-skilled workers working with heated iron and steel in forges, smithies and stamp shops.

Note that blacksmiths and other workers on the railways usually belonged to the railway unions instead of to trade-specific unions.

Associated Blacksmiths' Forge and Smithy Workers' Society and predecessors

This union existed in various incarnations:

• Scottish United Operative Blacksmiths' Protective and Friendly Society (1857-1873)
• Associated Blacksmiths of Scotland (1873-1885)
• Associated Blacksmiths' Society (1885-1909)
• Associated Blacksmiths and Ironworkers' Society (1909-1925)
• Associated Blacksmiths' Forge and Smithy Workers' Society (1925-1962)

It only had branches in Scotland until 1874, when it began to open a few branches in England and Ireland. It absorbed the Blacksmiths' Union in 1912, which expanded it nationally.

It originally only admitted skilled blacksmiths and other smiths, probably including benders, finishers, hammermen, stampers and welders. By 1925 its remit extended to oxy-acetlyene and electric welders and in 1950 to all forge and smithy workers (although it may well have covered all such workers in practice long before).

Genealogical sources exist for the entire history of the union.

Blacksmiths' Union

The Blacksmiths' Union was formed in 1911 by the amalgamation of two former unions, which had branches throughout England:

• Co-operative Society of Smiths (1849-1911)
• Combined Smiths of Great Britain and Ireland (1898-1911)

It only survived for a year before merging into the Associated Blacksmiths and Ironworkers' Society in 1912.

There is a list of all members on amalgamation in 1912, but no other genealogical sources.

United Kingdom Society of Amalgamated Smiths and Strikers

The United Kingdom Society of Amalgamated Smiths and Strikers was formed in 1886 and amalgamated with nine other unions on 1 July 1920 to form the Amalgamated Engineering Union. It seems to have accepted all forge and smithy workers as members.

The only genealogical sources relate to the Gloucester branch.

United Society of Boilermakers, Blacksmiths, Shipbuilders and Structural Workers and successors

In 1962, the Associated Blacksmiths' Forge and Smithy Workers' Society amalgamated to form the United Society of Boilermakers, Blacksmiths, Shipbuilders and Structural Workers. Since then, forge and smithy workers have belonged to the following unions:

• United Society of Boilermakers, Blacksmiths, Shipbuilders and Structural Workers (1962-1963)
• Amalgamated Society of Boilermakers, Shipwrights, Blacksmiths and Structural Workers (1963-1982)
• General, Municipal, Boilermakers and Allied Trades Union (GMB) (1982-present)

Genealogical sources exist from 1962 to 1984.

Amalgamated Engineering Union and successors

On 1 July 1920 the United Kingdom Society of Amalgamated Smiths and Strikers was a founder member of the Amalgamated Engineering Union. This has gone through the following incarnations, all of which recruited forge and smithy workers:

• Amalgamated Engineering Union (1920-1967)
• Amalgamated Union of Engineering and Foundry Workers (1967-1970)
• Amalgamated Union of Engineering Workers (1970-1986)
• Amalgamated Engineering Union (1986-1992)
• Amalgamated Engineering and Electrical Union (1992-2002)
• Amicus (2002-2007)
• Unite (2007-present)

Genealogical sources exist from 1920 to 1993.