Workbench Guides: Steel Welding 101

The History of Welding

  • Welding dates back thousands of years, with some early examples, such as gold circular boxes, being found from the Bronze Age. These first welders pressure-welded lap joints together to construct these boxes, which experts estimate were made more than 2,000 years ago. Egyptians and other people living in eastern Mesopotamia also engaged in welding of iron pieces to make tools.
  • Blacksmiths during the Middle Ages welded iron, but they used primitive techniques. Producing an arc between two carbon electrodes with a battery first occurred in 1800. Several decades later, an electric generator made it easier to produce arc lighting. It was also during this century that arc welding with carbon and metal arcs was developed.
  • During the 1880s, the first patents for welding were granted. These patents involved a primitive electrode holder, a precursor to carbon arc welding. In 1890, the first United States patent for arc welding with a metal electrode was granted.
  • Resistance welding was developed next, which included spot, seam, projection, and flash butt welding.
  • Automatic welding began in 1920, using bare electrode wire on direct current and adjusting arc voltage to regulate the feed rate. It was also around this time that other types of welding electrodes were developed.
  • During the following decades, stud, gas tungsten arc, and carbon dioxide gas welding were also developed. Friction or inertia welding is a newer process used when a high number of similar parts needs to be welded. Laser welding is a new type of welding used to cut metals and nonmetals.

Types of Welding

  • Arc Welding: Arc welding involves an electric arc used to create heat and melt or join metals. A power supply is required to create the electric arc.
  • Oxyacetylene Welding: Ocyacetylene welding is also called gas welding. This process uses the combustion of oxygen and acetylene in a torch or blowpipe, producing a hot flame.
  • High-Frequency Electric Resistance Welding: High-frequency electric resistance welding uses less heat because electromagnetic energy is used instead. Heat and pressure join material, which improves the weld properties.
  • Laser Beam Welding: Laser beam welding uses a laser beam to join thermoplastics or metals. The concentrated heat source of the laser beam enables joining thinner materials. For thicker materials such as tools, the laser beam creates a deep and narrow weld.
  • Ultrasonic Welding: Ultrasonic welding is a welding process used to join or reform thermoplastics. A high-frequency mechanical motion generates heat at the joint area to melt the plastic and form a molecular bond.
  • Solid-State Welding: Solid-state welding joins materials without using a vapor or liquid phase. This type of welding uses pressure, either with or without the use of temperature.
  • Electron Beam Welding: Electron beam welding involves minimal heat, resulting in a clean and precise weld. This type of welding is ideal for joining metals that are hard to weld together and dissimilar metals.
  • Gas Welding: With gas welding, the heat is produced from a gas or gases burned at a high temperature. Gas welding is ideal for welding pipes and tubes.
  • Underwater Welding: Underwater welding involves submersion of the welder, possibly at elevated barometric pressures. Underwater welding requires special training, and the welder must be a trained diver as well.

Welding Equipment and Safety

The inherent dangers of welding make it crucial to follow safety protocols and use proper safety equipment. Welders need protection from fumes, ultraviolet and infrared light, and hot metals. Welders also need extensive training to understand the processes and the hazards involved in working with radiation, explosives, and toxic environments.

  • Welding Helmets: Helmets protect the face and neck from radiation and sparks.
  • Eye and Face Protection: When a full helmet is impossible to wear, goggles and a face shield offer protection for the eyes and face.
  • Safety Glasses: Experts recommend that welders wear an extra pair of safety glasses under a welding helmet.
  • Gloves: Flame-resistant gloves the protect hands when working with radiation and intense heat.
  • Body Protection: Welding jackets offer flame-resistant protection while welding at a workstation.
  • Apron and Sleeves: Welders should wear an apron and sleeves under their welding jacket for extra protection of the chest and arms.
  • Respirator: Wearing a respirator offers protection from airborne particulates and fumes.
  • Welding Hat: A welding hat is worn under a helmet, offering additional protection from sparks.
  • Boots: Leather boots can protect the feet from heavy objects and sparks.

Welding Schools and Organizations

Additional Welding Information