Nepedia
Back to Discover
Fluent Reader
💻

Welding

technology Maturity 7-9 Next article →

Welding is a special way to join materials together. Most people use it to join metals or plastics called thermoplastics.

US Army soldier welding two metal pieces, Fort Gregg-Adams, Virginia, March 2025
US Army soldier welding two metal pieces, Fort Gregg-Adams, Virginia, March 2025

The main goal is to create a permanent bond. This is often done by using high heat to melt the parts. When the melted parts cool down, they fuse into one piece. This new joint can actually be stronger than the original metal.

Weld puddle, also known as a weld pool or welding pool
Weld puddle, also known as a weld pool or welding pool

How does this work step by step? First, a heat source melts the edges of the materials. This creates a liquid area called a weld pool.

GMAW weld area
GMAW weld area

Often, a person adds extra material called filler to the joint. This filler melts into the pool to help build the connection. A shield is also used to protect the hot metal. This shield keeps out things like oxygen that could ruin the weld.

SMAW area diagram
SMAW area diagram

People have been joining metals for thousands of years. In the Bronze Age, people used pressure to join gold.

Solid-state welding processes - AWS A3.0 2001
Solid-state welding processes - AWS A3.0 2001

During the Iron Age, blacksmiths used forge welding. They heated iron until it was soft and then hammered it together.

Iron Pillar, Delhi, May 2008
Iron Pillar, Delhi, May 2008

One famous example is the iron pillar in Delhi, India. It was built around 310 AD and weighs 5.4 metric tons. Later, scientists like Sir Humphry Davy and Vasily Petrov helped discover electric arcs. These discoveries led to the modern welding we use today.

Many different ways to weld exist now. Some use a gas flame, while others use an electric arc.

Acetylene welding on cylinder water jacket., 1918 - NARA - 530779
Acetylene welding on cylinder water jacket., 1918 - NARA - 530779

You can even use lasers or electron beams. During the 20th century, world wars made welding very important for building ships and planes.

AlfredPalmerwelder1
AlfredPalmerwelder1

New methods like submerged arc welding became popular for fast shipbuilding. Today, many big factories even use robot welding to do the work.

Welding is used to build almost everything around us. It helps make strong bridges and huge skyscrapers.

Maurzyce 2009 (0)
Maurzyce 2009 (0)

In the past, people used rivets or bolts to hold metal together. But those connections could sometimes fail under pressure. Welding allows for lighter and stronger shapes. It is even used in extreme places like underwater or in outer space!

Working Diver 01
Working Diver 01

Because it uses intense heat and light, workers must be very careful. They wear special gear to stay safe from burns and bright light.

362 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (25)
File:G502 Overhead.jpg
G502 Overhead.jpg
File:US Army soldier welding two metal pieces, Fort Gregg-Adams, Virginia, March 2025.jpg
US Army soldier welding two metal pieces,...
File:Iron Pillar, Delhi, May 2008.jpg
Iron Pillar, Delhi, May 2008.jpg
Welding the Big Ring - Westinghouse Works.webm
File:Acetylene welding on cylinder water jacket., 1918 - NARA - 530779.jpg
Acetylene welding on cylinder water...
File:Maurzyce 2009 (0).jpg
Maurzyce 2009 (0).jpg
Portable welder Sydney Water Photograph...
MIG welding.webm
File:Oxyfuel gas welding operation-no.svg
Oxyfuel gas welding operation-no.svg
File:Weld puddle, also known as a weld pool or welding pool.png
Weld puddle, also known as a weld pool or...
File:SMAW area diagram.svg
SMAW area diagram.svg
File:GMAW weld area.svg
GMAW weld area.svg

+ 13 more

More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.