There was once a time, in antiquity, when a blacksmith needed hotter temperatures than his fire could do on its own. A fire then was sparked by various materials, including, possibly coal. For a blacksmith who needed a burst of flame, he would rely on a particular tool to give a blast of air and raise the temperature of the fire: the bellows.

A bellows defined is a device that is used to furnish a blast of air. The simplest type, one that was seen in antiquity, is an inflatable bag attached to two pieces of wood. When the pieces of wood are drawn outward, the bag inflates with air. When the two pieces of wood were then pushed together, the air was pushed out “in a blast.”

The term bellows has since been used to describe any bag that changes in volume, and is sometimes used to describe the bag inside a camera that compresses and decompresses according to different photography techniques. But generally speaking, it is used most often to describe the previous description, as a tool for blasting air.

Oftentimes, bellows just have one type where the air is pushed out through a valve. But there are some bellows, likely modern bellows that have been used for some type of metallurgy, that use multiple tubes, the bellows then being called a multi-ply bellows. A multi-ply bellows uses two to three tubes but many can contain as many as five tubes.

A multi-ply bellows or a general bellows is usually associated with a type of practice called metallurgy, or the working and crafting of metals. Several processes in metallurgy have to do with elevating the level of heat and it is possible require a bellows, whether that bellows is a multi-ply bellows or a bellows seen in antiquity.

These processes include smelting, which is a process that takes an ore (perhaps iron or copper) and melts it down to its base metal. Iron ore typically melts at 2,750 degrees Fahrenheit, while steel typically has a melting point of 2,500 degrees Fahrenheit. While these temperatures are tough to reach, a modern multi-ply bellows can reach them.

Welding is another process that often includes the need of a bellows. Welding is the process of joining two materials together and those materials need to be at certain melting points for that attaching to occur. Welding has many uses for a bellows; it can heat up the process enough for the melting to occur.

Bellows are deliver additional air to the fuel, raising the rate of combustion, and therefore the heat output. Various kinds of bellows are used in metallurgy, including box bellows in East Asia, Tatara foot bellows in Japan, accordion bellows which are used in Europe, and more modern ones in America.

A custom bellows design requires focus on 12 vital attributes: stress modes, flexing, pressure differential, rigid stops, spring rate, life cycles, temperature extremes, exposure, assembly method, vibration, end configuration, and geometric constraints. These are all extremely important to a bellows’ functioning.

There are many different names of bellows, each term signifying a different adjustment to the bellows that has been made:

• Exhaust bellows
• Metal bellows
• Standard bellows
• Stainless steel bellows
• And more

Bellows also have different uses than just metallurgy. They include:

• Anesthesia machines
• Cuckoo clocks
• Reed organs
• Pipe organs
• Harmonium

And more there are well. Bellows, or the technology behind bellows, can be used for different purposes in different industries, wherever there is a need for air to be pushed out rapidly through a valve by using an inflatable bag-like structure, as is seen in the traditional bellows.

There are certain aspects of technology that change, such as the amount of tubes in a bellows (for instance, in the case of the multi-ply bellows) or in the material being used to let the bellows function, as it changes from culture to culture and country to country. But bellows are an incredibly useful tool when it comes to metallurgy especially.

Bellows improve the metallurgist’s ability to raise the temperature of the heat source that he or she is using; a metallurgist then can weld and smelt and perform other important metallurgy functions, that would otherwise be impossible with a standard level of heat.

Bellows are integral to metallurgy and help with the melting of metals in order to form them into something else.