745 Welding, Cutting, and Brazing Safety

Cutting

Oxyacetylene Cutting (OAC)

Oxyacetylene cutting uses a mixture of acetylene and oxygen to generate a high-temperature flame (up to 5,580°F / 3,082°C).

The flame is directed onto the metal to heat it until it melts. Then, a jet of pure oxygen is applied to blow away the molten metal, effectively separating the workpiece.

This method is widely used for cutting ferrous metals, especially steel, due to its ability to cut thick materials with precision. Common applications include: cutting thick steel plates, and heavy industrial work such as in shipyards and construction.

Oxypropane Cutting (APC)

The flame produced is slightly cooler (around 4,600°F / 2,538°C), making it less suitable for cutting very thick metals.

However, it is a cost-effective alternative for cutting mild steel and non-ferrous metals like aluminum and copper. Propane is cheaper than acetylene, and it produces a cleaner, less sooty flame.

Common applications include: Cutting scrap metal, mild steel or non-ferrous metals like copper and aluminum, and maintenance work.

Air-Acetylene Cutting (AAC)

Air-acetylene cutting uses acetylene mixed with atmospheric air (no pure oxygen). The flame is significantly cooler (around 4,000°F / 2,204°C), making it suitable for lighter-duty cutting and not effective on thick metals.

This method is ideal for thin sheet metal or for use in tasks requiring portability, such as pipe cutting, or work in tight locations like confined spaces.

Carbon Arc Cutting (CAC)

Carbon Arc Cutting (CAC) is a thermal cutting process that uses an electric arc and compressed air to remove metal. The arc melts the metal, and a high-velocity air stream blows the molten material away, creating a clean cut or groove.

This method is widely used in metal fabrication, shipbuilding, and industrial maintenance to remove old or damaged welds, gouge cracks, and prepare surfaces for welding. It is also employed in demolition and repair operations where precise metal removal is necessary.

Plasma Arc Cutting (PAC)

Plasma Arc Cutting (PAC) is an advanced thermal cutting process that utilizes a high-velocity jet of ionized gas, known as plasma, to cut through electrically conductive materials.

This method is highly effective for cutting metals such as steel, stainless steel, aluminum, brass, and copper, making it popular in various industrial and fabrication settings.

The process works by generating an electric arc between a non-consumable tungsten electrode inside the torch and the metal workpiece. As the arc forms, it passes through a narrow nozzle, forcing the gas (commonly air, nitrogen, oxygen, or a mixture like argon-hydrogen) to become ionized, turning it into plasma. This plasma stream can reach temperatures of up to 30,000°F (16,650°C), which melts the metal at the point of contact.

At the same time, the high-velocity jet of plasma and compressed gas blows the molten metal away from the cut, producing a clean and precise separation. PAC is widely used in industries such as automotive repair, shipbuilding, aerospace, metal fabrication, and construction because of its ability to make fast and accurate cuts on a variety of metal thicknesses.

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