Forge welding predates written history by several thousand years. Bronze Age metalworkers used heat and hammer blows to join copper and gold without any filler metal, producing vessels and tools that survive in museum collections.
The modern story is not a straight line. Arc welding, oxy-fuel, resistance welding, MIG, TIG, and friction stir each arrived in response to specific industrial pressures, from boiler failures, wartime production demands, and later safety codes. Soldering and brazing followed older, lower-temperature paths that remained useful in electronics and plumbing.
The result is a craft whose timeline runs through shipyards, pipelines, and aerospace shops, not through a single inventor's workshop.
The Forge and the Flame: Welding From the Middle Ages and Earlier
Welding, at its core, is the joining of two pieces of metal into one continuous body by applying heat, pressure, or both until the material fuses, a definition that anchors any Introduction to Welding. Long before electricity or pressurized gas, that fusion happened at the blacksmith's fire, and it is where the story of the trade begins. But sorting genuine welding from its close cousins, soldering and brazing, matters here, because much of what looks like ancient welding turns out to be something else.
When Did Metal Joining Start?
The temptation is to name a single origin date, but the archaeological record resists it. The famous Royal Cemetery at Ur, in ancient Mesopotamia, produced spectacular metalwork excavated by C. Leonard Woolley in the 1920s and 1930s under a joint Penn Museum and British Museum project, with finds later divided among the Iraq Museum, Penn, and the British Museum. The graves date mainly to around 2600 to 2500 BC. The goldwork found there is remarkable, but technical study shows it was assembled by mechanical attachment and soldering rather than by the different types of welding that fuse metal.2 So while you will often read that welded gold boxes from Ur date to 3000 BC, that specific claim is not well supported by the evidence.
Egyptian iron tells a similarly cautious story. Tutankhamun's iron dagger, from roughly 1334 to 1325 BC3, was made from meteoritic iron and shaped with low-temperature heating around 700 to 950 degrees Celsius, not routine smelting and forging. Indigenous iron smelting in Egypt appears much later, and common iron tools only became widespread around 700 to 800 BC.5 The iron plate from the Great Pyramid held by the British Museum has been reassessed as probably far more recent than the pyramid itself.6 In short, iron working developed gradually and unevenly.
Casting, Not Welding, in Early China
Ancient Chinese bronze offers another lesson in reading artifacts carefully. The great ritual vessels of the Shang and Zhou periods were produced by piece-mold casting7, and the raised ribs sometimes visible on them are mold-section seams, not welds.8 Where separate components were joined, the techniques were soldering, brazing, running on molten metal9, or a cast-in method sometimes described as cast-welding, as seen on certain vessels.10 These are metallurgical joins, but not the heated-and-hammered forge welding of a smith.
The Blacksmith's Forge Weld
Forge welding is the method that dominated through the Middle Ages. The blacksmith heated two pieces of iron or steel to a bright, near-molten yellow-white, often coated the surfaces with flux to keep away scale, then hammered them together on the anvil until they fused into a single mass. It demanded judgment: too cool and the joint failed, too hot and the metal burned. This hammer-and-heat approach remained the primary way of welding metal for centuries, until the industrial era introduced the flame and the arc.
From Acetylene to MIG: How Modern Welding Took Shape
Flame or arc: for the better part of a century, welders and engineers argued over which one deserved to be the trade's future. The answer, it turned out, was both, and the argument itself pushed the craft forward faster than either technology could have managed alone.
Flame first: acetylene and the oxy-fuel torch
Acetylene gas was identified by Edmund Davy back in 1836, but it sat around as a chemistry curiosity for over sixty years. It wasn't until roughly 1900, when a workable blowtorch finally combined acetylene with oxygen in a controllable flame, that oxy-acetylene welding and cutting became a practical shop process.2 That torch gave fabricators a portable, intensely hot flame capable of melting steel cleanly, and it spread quickly through shipyards, railroads, and machine shops.
The arc arrives: resistance and carbon-arc welding
While the torch was still being refined, electricity was opening a second front. Nikolai Benardos and Stanislaw Olszewski patented carbon-arc welding in 1881, striking an arc between a carbon electrode and the workpiece to fuse metal directly.1 Elihu Thomson followed with resistance welding, patented between 1885 and 1900 (with a key successful patent in 1886), which used electrical resistance and pressure rather than an open flame or arc to join metal.1 In 1888, Nikolai Slavyanov advanced the idea further by introducing a bare metal electrode that melted into the joint itself, an early step toward the consumable-electrode arc welding used today.1
The welding battle
By the early 1900s, shops effectively had to choose sides. Oxy-acetylene offered portability and fine control, useful for thin sheet and repair work. Electric arc processes offered deeper penetration and speed on heavier steel. Manufacturers, trade schools, and even trade journals debated which method would define industrial fabrication, and for a couple of decades neither side fully won. The eventual answer was specialization: arc welding took over structural and shipbuilding work, while gas welding held its ground in maintenance, HVAC, and thin-metal trades.
War work: welding proves itself
Two world wars settled a lot of the argument by necessity. Riveted ship hulls were slow to build and vulnerable to failure, and welded construction let shipyards assemble sections faster and with fewer bottlenecks. Wartime demand pulled enormous numbers of new welders into welding jobs: Bureau of Labor Statistics figures show shipbuilding welders and burners in the United States jumped from around 9,000 to roughly 180,000 by December 1943, a workforce expansion that opened welding to women in large numbers for the first time.5 One documented C-1 cargo ship alone carried about 207,000 linear feet of welding, over 41,500 feet of it laid down by automatic Unionmelt equipment.2 Welded hulls weren't flawless (one shipbuilding study tracked 25 failures across 4,694 welded ships)6 but the process had proven itself at industrial scale.
TIG, MIG, and the postwar leap
Aircraft manufacturing pushed the next leap. Russell Meredith at Northrop Aircraft Company developed gas tungsten arc welding, TIG Welding, around 1940 to 1941, using a non-consumable tungsten electrode shielded by inert gas (originally helium, hence the early trade name Heliarc) to join magnesium and aluminum airframes cleanly.3 Battelle Memorial Institute followed in 1948 with gas metal arc welding, MIG Welding, feeding a continuous consumable wire electrode through a shielding gas envelope.4 Together they gave postwar industry the precision and speed that oxy-fuel and carbon-arc methods alone never could.
Welding Timeline: Key Dates and Inventions
Welding Vs. Soldering Vs. Brazing: A Historical Divergence
Welding, brazing, and soldering are often lumped together as "metal joining," but they split apart thousands of years ago and never fully reunited. Each method is defined by a different relationship between heat, filler, and the base metal itself, and that distinction shaped which industries adopted which process.
Three Ways to Join Metal
The Art of Welding coalesces the base metal directly, either molten or heated to a plastic state, often without any filler at all. Temperatures typically run 1,300 to 1,500 degrees Celsius, and forge welding specifically required metal heated to roughly 1,350 degrees before hammer blows could fuse the joint. Soldering and brazing never melt the base metal. Instead, a filler flows into the joint by capillary action while the parent pieces stay solid. The dividing line between the two is temperature: fillers melting at or below about 450 degrees Celsius count as soldering, while anything hotter, often approaching 900 degrees in ancient "hard soldering" practice, is what we'd now call brazing.
Soldering's Long, Quiet History
Soldering is the oldest of the three by most accounts, though the earliest evidence is necessarily incomplete since low-melting fillers and organic fluxes leave little archaeological trace. The clearest early record comes from Ur, where third-millennium BCE goldsmiths joined electrum and gold jewelry using natural alloys and copper-bearing solders, sometimes alongside soldering, pressure joining, or mechanical assembly without a strong preference for one over another. That jewelry-first pattern held for millennia. Soldering later found its industrial home in plumbing and, far more consequentially, in electronics, where fillers like tin-lead alloys and modern lead-free options such as SAC305 or bismuth solders hold circuit boards together today.
Brazing's Middle Ground
Brazing occupies the temperature zone between soldering and welding, and it too has ancient roots. Jewelry from Qurneh in Egypt shows hard-soldered, effectively brazed, joints using gold and electrum alloys with added copper to lower the melting point, evidence of high-temperature filler joining that predates any single claim to invention. Brazing never disappeared; it simply moved into different applications, from HVAC tubing and bicycle frames to carbide cutting tools, using fillers like silver, copper, brass, or copper-phosphorus alloys.
Welding took a separate industrial path entirely, tied to iron and steel rather than precious metals. Unlike Stick Welding, forge welding of iron is generally associated with early ironworking in Anatolia around 1800 BCE, though the exact date and origin remain debated among researchers, and it would take another three thousand years before welding overtook soldering and brazing as the dominant method for structural steel, shipbuilding, and pipelines.
Who Invented Arc Welding? Resolving the Attribution
The year 1881 anchors the answer, but the full story spans three names and two distinct methods. Nikolai Benardos and Stanisław Olszewski developed the first practical carbon-arc welding process between 1881 and 1882, while Nikolay Slavyanov advanced the consumable metal electrode in 1888. Sorting out who invented arc welding requires separating scientific demonstration from patented, usable process, and carbon electrodes from metal ones.
Davy Made the Arc, Not the Weld
Humphry Davy demonstrated the electric arc as early as 1800 and produced a sustained public arc in 1808. These were landmark scientific achievements, but they were laboratory phenomena, not joining processes. No documented record shows Davy using his arc to weld metal. He proved the arc existed and could be controlled; turning it into a repeatable way to fuse two pieces of steel came decades later. Crediting Davy with inventing arc welding overstates what the historical record supports.
Carbon Arc: Benardos and Olszewski
The first practical arc welding system used a carbon electrode. Benardos and Olszewski named their method Elektrogefest and secured patent protection on both sides of the Atlantic. Their British patent, No. 171,596, was dated 10 October 1885. The U.S. patent, No. 363,320, titled "Process of and Apparatus for Working Metals by the Direct Application of the Electric Current," was filed in 1886 and granted on 17 May 1887.1 A carbon rod served as one pole of the circuit, striking an arc against the workpiece, with filler added separately.
One caution on attribution: the process is often credited to Benardos alone, which erases his co-inventor. The joint patent record names both N. N. Benardos and S. Olszewski. For carbon-arc welding, the defensible attribution is the pair, not the individual.
Metal Electrode: Slavyanov
Slavyanov took the next step in 1888 by using a consumable metal electrode, a rod similar in composition to the workpiece that served both as the second pole and as filler material. This is the ancestor of nearly every modern process, including MIG Welding Techniques and FCAW Flux Cored Arc Welding. Russian institutional sources date his first practical demonstration, welding a steam-engine crankshaft, to 18 October 1888, though other accounts place it elsewhere within that year. A patent is reported for 1890, but no verified patent number survives in the available materials, so we do not assign one here.
One more name deserves clarity. Charles L. Coffin received U.S. patent No. 428,459, "Process of Welding Metals Electrically," on 20 May 1890.3 That is Coffin's work and should not be conflated with Slavyanov's earlier demonstration.
The clean answer: carbon-arc welding goes to Benardos and Olszewski; the consumable metal electrode goes to Slavyanov.
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Beyond the West: Non-Western Welding Traditions and Women in Welding
Most Western-authored welding histories still open in 19th century Europe, but that framing skips roughly three thousand years of forge welding developed independently across Asia and Africa, and it undercounts the wartime workforce that industrialized the craft in the United States. The record on both fronts is uneven, but the outlines are firm enough to correct the story.
Asian and African Forge Welding
South Asian smiths were joining wrought iron on a monumental scale well before European guilds formalized the trade. The Iron Pillar of Delhi, dated to roughly AD 400, rises more than seven metres and was forge-welded from small bloomery blooms, without passing through a cast-iron stage. The Puri iron beams, constructed sometime between AD 640 and 1174, extend that tradition to structural spans. India is also the most commonly cited origin for crucible (wootz) steel, though scholars describe the attribution as circumstantial rather than settled.
Japanese swordsmiths refined the same underlying idea into a repeated forge, weld, and reforge cycle that consolidated uneven bloomery iron and combined hard and soft layers. Bloom welding for large forgings persisted in Japan into the mid-19th century.2 Chinese ironworkers ran small blast furnaces early and produced large wrought-iron structures by welding smaller masses together, a practice that likewise continued until roughly the mid-19th century.2
African metallurgy runs deeper still. UNESCO places iron reduction in parts of Africa as early as the 3rd millennium BC, contemporaneous with or possibly earlier than western Asia.3 African smiths both soldered and forge-welded, producing composite blades with harder cutting edges attached to lower-carbon bodies. Chronology and workshop organization vary widely across the continent and are not fully mapped.
Women in the Welding Workforce
During World War II, more than six million American women took paid defense jobs, with roughly ten million more in volunteer roles.4 Kaiser's Vancouver yards employed over ten thousand women by 1944;5 Pittsburgh-area women built LSTs at Dravo and American Bridge;6 and workers at the J.A. Jones Brunswick shipyard helped push ship completion under two months.7 Vera Anderson, nineteen, won a "World's Champion Welder" title in 1944 with a $350 war-bond prize.8 Florence DiTullio Joyce entered Fore River shipbuilding at eighteen.8 Virginia L. Wilder Parker qualified as a welder, second class, one of seven women promoted to that grade.9 The welding engineer Brennecke was consulted by NASA in 1961.10 Gender barriers pushed most of these workers out after 1945, and formal recognition of their contributions is largely a 21st-century development.
Evolution of Welding Safety Standards and Certification
Welding safety standards grew from early boiler failures into a formal system of codes and certification. The table below highlights key milestones in the development of welding standards, from the first ASME boiler code to modern AWS standards and federal workplace safety rules.
| Year | Standard/Certification | Organization |
|---|---|---|
| 1911 | ASME proposed creation of the Boiler Code | American Society of Mechanical Engineers (ASME) |
| 1914 | First edition of the ASME Boiler and Pressure Vessel Code issued (1914 Edition) | American Society of Mechanical Engineers (ASME) |
| 1915 | 1914 Edition published as a 114-page book | American Society of Mechanical Engineers (ASME) |
| 1919 | American Welding Society founded as a nonprofit organization advancing welding and allied joining and cutting processes | American Welding Society (AWS) |
| 1928 | Predecessor of the AWS D1.1 Structural Welding Code published | American Welding Society (AWS) |
| 1970 | Occupational Safety and Health Act enacted, establishing federal workplace safety regulation | Occupational Safety and Health Administration (OSHA) |
| 2026 | AWS has authored more than 350 standards for welding practices and procedures | American Welding Society (AWS) |
Common Welding History Questions Answered
Readers researching the craft often circle back to the same handful of questions. Here are direct answers, drawn from the timeline covered earlier and key facts about welding.
When did welding start?
The earliest physical evidence of joined metal dates to roughly 3000 BC, with small gold boxes and ornaments assembled using pressure and heat. Egyptian and Mediterranean smiths refined these techniques over the following millennia, and by the Middle Ages, forge welding (hammering heated iron pieces together on an anvil) was the standard method for joining metal across Europe, the Middle East, and Asia. So while the tools have changed dramatically, the underlying idea of fusing two pieces of metal into one is about 5,000 years old.
When was arc welding invented, and who invented it?
The first practical carbon-arc welding process was patented in 1881 by Nikolai Benardos and Stanisław Olszewski, who used a carbon electrode to strike an arc against the workpiece. Later refinements by Nikolai Slavyanov (metal electrode, 1888) and Charles Coffin in the United States built on that foundation. Benardos and Olszewski are generally credited with inventing practical carbon-arc welding, though the modern process is a composite of several contributors.
What is the difference between welding, soldering, and brazing?
The distinction comes down to temperature and whether the base metal melts:
- Welding: The base metals themselves melt and fuse together, usually with a filler rod of similar composition. Temperatures typically run 1,300 to 1,500 degrees Celsius.
- Brazing: A filler metal with a melting point above 840 F flows into the joint by capillary action. The base metal stays solid.
- Soldering: Similar to brazing, but the filler melts below 840 F. Common in electronics and plumbing.
Welding produces the strongest joint because the parent material is part of the bond. Soldering and brazing are gentler on the base metal and better suited to dissimilar or heat-sensitive materials.
Who invented MIG welding?
Gas Metal Arc Welding, commonly called MIG Welding, was developed in the 1940s at the Battelle Memorial Institute under a project sponsored by the Air Reduction Company. It was patented in 1949 and initially used inert gases like argon to shield the arc when welding aluminum and other non-ferrous metals.
How did welding change during the World Wars?
Both wars accelerated the shift from riveting to welding for ship and vehicle construction. The most dramatic example is the American Liberty ship program of World War II, which produced 2,710 welded cargo ships between 1941 and 1945, some assembled in under two weeks. Welding cut labor hours, reduced weight, and made mass production of hulls, tanks, and aircraft possible at a scale riveting could never match.