All about Copper Alloy Ingot and Castings – usage and standards from World War 2

Ingots are materials, mostly metal, that are cast into blocks or bars suitable for further processing.

Various copper alloy ingot manufacturers emphasise that their products conform to recognized international standards such as BSI’s. They are extensively used for manufacturing of gear, pumps, valves, marine parts and many other industries.

Copper alloy ingots can include bronze, gunmetal and brass. 

Bronze Ingots are a durable material made from copper and tin dusts in a crafting grid or Metallurgic Infuser.  They are of high strength, and are extensively used in castings for boiler mountings, water pressure fittings and grease and oil lubricated bearings.

Gunmetal is a type of bronze, being an alloy of copper, tin, and zinc. The ingots are used for plumbing gears, valves, hydraulic castings, steam casting and in cheap jewellery.  It was originally used mostly in making guns, hence the name, but was eventually superseded by steel.

Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. Brass ingots can be used for valves, pumps, supply-water faucets, bearings, and pressure seal casting.

Castings

The casting process involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and allowing it to cool and solidify. The solidified part is also referred to as a “casting”.  It is ejected or broken out of the mold.  Casting is usually used for making complex shapes that would be difficult or uneconomical to make by other methods.

Castings vs. Ingots

When castings are made, the product is almost complete as the mold has the shape of the desired component.  All that needs to be done afterwards are the various finishing operations.  Ingots are produced through “continuous casting”, and are in effect large rough castings designed for storage and transportation.  They need be hammered or pressed into shapes later on.

Emergence of British Standards in World War 2

With a breakout of the Second World War, there was an urgent need in the UK to economise in the consumption of virgin metals, especially tin, and to utilise to the best advantage the supplies of bronze and brass scrap in their place.  Restrictions on the use of high-grade gun metals, which consisted of 10 percent tin, were in place.

A War Emergency Standard was required to bring into use gun metals and bronzes of lower tin contents than had been customary in Great Britain at the time, and to extend the uses of cast brasses made from scrap from machining operations.

In May 1942, BSI’s Non-ferrous Metallurgy Industry Committee developed the War Emergency Standard for Copper Alloy Ingots and Castings – it was actually eight single page specifications numbered BS 1021 to BS 1028 in one document.  It provided specifications for gunmetal, leaded gunmetal and brass ingots and castings, with a much lower percentage of tin in the gunmetal. These economies remained in place throughout the duration of the war.

In 1944 the standard was re-issued as hostilities continued, and further restrictions were made, with lower levels of lead in leaded gunmetal, and lower levels of tin in all ingots and castings.

Post-war standards

Following the war, the BS 1021-1028 specifications were replaced with BS 1400 in 1948, bringing all specifications into one volume.  Specifications were expanded significantly to cover for phosphor bronze, silicon, high tensile and die-castings.

New editions of BS 1400 were issued in the 1960s, 70’s and 80s, with the range of alloys increasing over time.

In 1998 a new European standard EN 1982 was published, for copper alloy ingots, and copper and copper alloy castings.  It was based on previous national standards and harmonized the compositions and mechanical properties required.  BSI adopted this in 1999.

The current version, adopted by BSI is BS EN 1982:2008, and our Copper and Copper Alloys committee contributes to its development.

What’s available in the Knowledge Centre?

BSI’s Knowledge Centre can provide access to the withdrawn editions of BS 500 back to 1933. Members can view withdrawn publications without charge in Chiswick, and they are available for purchase in hard copy and PDF.  BSI members receive a 50% discount, free postage and can buy on account.

To find out more please contact the Knowledge Centre at: knowledgecentre@bsigroup.com or on +44 (0)20 8996 7004


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