What is Welding? The Ultimate Guide

October 2, 2019

Updated 8/21/2023

Welding serves as the foundation for many metal fabrication processes. Today, skilled professionals can weld metal by hand or with automation to form parts and products. At Fairlawn Tool, Inc., we perform manual and robotic welding as part of our services. This guide will provide an overview of the history of welding, how it works, different methods, materials used, and its use in an industrial context.

The History of Welding

As you might imagine, welding has been around for quite some time. We can assume it existed in some form as far back as the Iron Age and the Bronze Age. There is evidence that the Egyptians learned to weld iron together, and we have found small gold boxes with pressure-welded lap joints from over 2,000 years ago.

However, the type of welding prevalent then and during the Middle Ages was a very rudimentary type of welding that typically involved hammering two pieces of metal together under heat until they joined. Conventional welding as we know it did not appear until the 19th century.

History Of Welding Timeline

Welding history is a rich study of human ingenuity and spirit. After its invention, welding continued to evolve, bringing it to its modern-day form. Ancient welding looks a lot different than it does now. But each step in the welding timeline is an impressive leap in mechanical engineering. Here are some of the pivotal moments in welding history.

  • 4000 BCE: Historians believe the ancient Egyptians developed the earliest forms of welding around this time. Civilizations started welding with copper, and over time, moved on to other metals like iron, bronze, gold, and silver.
  • 3000 BCE: The Egyptians used charcoal to generate heat to turn iron ore into a loose substance called “sponge iron.” They then hammered the loose particles together to join pieces in the first instance of pressure welding.
  • 1330 BCE: The Egyptians began soldering and blowing pipe, joining pieces of metal together.
  • 60 CE: The historian Pliny recorded information about the gold brazing process. He included information about using salt as flux and even mentioned how a metal’s color reveals its brazing difficulty.
  • 310 CE: Indian welders created the Iron Pillar of Delhi, which still stands today, using iron from meteorites. The Pillar remains an impressive display of early craftsmanship, at 25 feet high and six tons in weight.
  • 1375 CE: Forge welding was at the forefront during this period. Blacksmiths would heat metal pieces and pound them together until they bonded.
  • The 16th century: Welders advanced in their craft during this period. Manuscripts from this century included the first references to the word “weld.” The Italian goldsmith Benvenuto Cellini wrote about a soldering process used for brazing silver and copper.
  • The 18th century: Welding technology skyrocketed in the 18th century due to the Industrial Revolution, which paved the way for the society we know today. Industries needed more advanced welding practices to achieve their goals. Welders developed innovative welding technologies to meet this demand. A couple of new advances included the development of blast furnaces and the discovery of oxygen.
  • The 19th century: This century saw the discovery of the electric arc by Sir Humphry Davy. Other inventors also innovated and patented fusion welding, bare metal electrode welding and carbon arc welding. Robbers used a torch to break into a bank vault, providing the first look at purposely using torches to melt metal.
  • The 20th century: Thermite welding first emerged in 1903. In 1919, C.J. Holslag invented alternating current welding, replacing electric arc welding as the most prevalent form of welding in the United States. Welding continued to increase and was in high demand due to the First and Second World Wars. President Woodrow Wilson established the United States Wartime

How Does Welding Work?

The welding process involves a variety of approaches and joint types. Techniques for welding can fall into one of two broad categories:

  • Fusion welding: As the most commonly known form of welding, fusion welding uses extreme heat to join metal pieces. The welder can use an inert gas or filler metal to strengthen the bond.
  • Pressure welding: During the pressure welding process, the welder applies external pressure to the two pieces. Pressure welding can happen at a temperature below the material’s melting point in a process known as solid-state welding.

Welders use fusion welding in a wide range of applications for many industries. Pressure welding techniques tend to involve specialized methods that suit more niche applications. Types of joints formed in welding include:

  • Butt joint: 135-180° angle connection between two ends
  • Lap joint: 0-5° angle connection between two overlapping parts
  • T joint: 5-90° angle connection between one part’s edge and the other’s face
  • Corner joint: 30-135° connection between two ends or edges
  • Edge joint: 0-30° degree connection between two edges

Since welding involves multiple techniques and connections, it’s used in numerous applications.

Types of Welding

  • Gas Metal Arc Welding/Metal Inert Gas Welding (MIG)

This is a type of welding that uses a wire attached to an electrode current to join two pieces of metal together. A shielded gas along the electrode heats up the two metals you are fusing. You would use this type of welding in industrial situations when fusing stainless steel or aluminum. Gas metal arc welding requires a direct current power source with constant voltage.

  • Tungsten Inert Gas Welding/Gas Tungsten Arc Welding (TIG)

This is similar to the above except you are using a tungsten electrode which heats the base metal to create a molten puddle. Because of this, you can create an autogenous weld where you simply join the two pieces together with the molten base metal as your joining material. This is a more complex welding process that an expert welder would use when you need a seamless join with a superior finish. Click here to learn more about the differences between MIG and TIG welding!

  • Shielded Metal Arc Welding (SMAW)

Sometimes just called arc welding, or occasionally “stick,” this is a very basic type of welding where the welder uses a stick with an electric current that creates an arc between the stick and the two metals you are joining. This is an effective method of welding steel or iron in construction, manufacturing, repair, and other industrial applications.

  • Fux-Cored Arc Welding (FCAW)

Flux-cored arc welding was created as an alternative to shielded metal arc welding or metal inert gas welding. However, instead of shielded gas to heat the metal, flux-cored arc welding uses a tubular wire filled with flux. Flux-cored arc welding is quite easy to learn and implement. It’s also cost-effective, but it does not always produce as high-quality or attractive a weld as other methods. For that reason, it’s usually used in construction projects where speed and flexibility are a priority over aesthetics.

  • Stitch Welding

Stitch welding is also known as intermittent welding. The reason for this name is that a stitch weld is not continuous along a joint. You’ll find gaps in stitch welding, which make it look like stitching. A stitch weld is not as durable as a seam weld because of these gaps. A stitch weld is most often used when the durability of a seam weld is not needed, or when you need to prevent heat distortion.

  • Seam Welding

What we call seam welding is also known as continuous welding. Seam welds, like stitch welds, can be used to form fillet and butt joint welds – the only difference being that there are no gaps or spaces. Seam welds are far more durable than stitch welding because of the integrity of continuous seaming.

Best Materials for Welding

  • Steel and Stainless Steel

Most suitable welding techniquesSMAW, DC-TIG, MIG, FCAW, resistance

Iron-based metals such as steel and stainless steel tend to work with the highest number of techniques compared to others. Low-carbon mild steel acts as one of the most weldable metals available. Its composition includes low amounts of elements that can decrease the risk of a failed weld. Stainless steel has a more complex chemical composition, but it can also work with multiple techniques that account for oxidation.

  • Aluminum

Most suitable welding techniques: SMAW, AC-TIG, MIG

Grades of aluminum that fall in the 1XXX and 6XXX series can undergo select welding techniques. A 1XXX series aluminum does not require much extra effort during the welding process, making it simple to handle. Meanwhile, a welder can work with 6XXX aluminum if they use proper welding operations and filler material.

  • Titanium

Most suitable welding technique: DC-TIG

When a welder protects titanium from oxidation, they can use it to achieve sturdy and long-lasting results. Titanium requires full coverage from a shielding gas to provide a high level of weld integrity.

  • Cast Iron

Most suitable welding technique: SMAW

Cast iron poses more difficulty during the welding process than metals such as steel or aluminum. Its high carbon content requires careful preheating and heating methods that provide gradual temperature changes.

  • Copper and Brass

Most suitable welding technique: DC-TIG

Copper and brass have high corrosion resistance which makes them useful for a variety of welding applications. During the welding process, the welder needs to account for any alloys in the material that cause cracks or oxidation.

  • Magnesium Alloy

Most suitable welding technique: AC-TIG

A magnesium alloy has similar properties to aluminum. The magnesium in the alloy has a much lower melting point than oxides, making it critical to remove oxides before welding.

Choose Fairlawn Tool for your Modern Welding Needs

Welding has become a more streamlined process with each passing century. Welders of the past could have only dreamed about our modern-day advances. When your business needs medium or large-scale welding services, Fairlawn Tool is the company to call.

We provide high-quality automated welding and cutting, along with tube bendingCNC turret punching, and a wide array of other state-of-the-art metal fabrication services to meet your metalworking needs. To learn more about welding and other metal fabrication processes, or to find out how Fairlawn Tool can help your business, contact us today.

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