Uses of Iron: 5 Main Uses Ranked by Steel Demand

The main use of iron is steel. Nearly all iron ore is turned into iron metal and then into steel: the US Geological Survey (USGS) reports that 98% of US iron ore products went to steelmaking in 2025, and only 2% to other uses. Steel then goes mostly into five groups of products. This five-use grouping is ours: we merged the seven sectors the World Steel Association publishes. Using the association’s 2025 shares of world steel use, they are buildings and infrastructure (52%), transport (17%), machinery (16%), metal products (10%) and electrical equipment and appliances (5%).

This page ranks those five uses with the numbers behind them, explains the difference between iron, steel and cast iron, covers the small uses that are not steel (pigments and the human body), and then shows where the ore comes from and what it costs. If you are asked for “two uses of iron” or “three uses of iron” at school, jump to the short answers section below.

Uses of iron: the five main ones, ranked by steel demand

The World Steel Association counted 1,718.2 million tonnes (Mt) of steel used worldwide in 2025 and split it by sector (World Steel in Figures 2026). The shares are the best single answer to “what is iron used for”, because steel is the form in which iron reaches almost every buyer. The table is our own grouping of the seven sectors the association publishes (building and infrastructure, mechanical equipment, metal products, automotive, other transport, domestic appliances, electrical equipment) into five uses.

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Share of world steel use by sector

Percent of 1,718.2 million tonnes used in 2025; seven sectors grouped into five uses

By our arithmetic on the same data, 52% of 1,718.2 Mt is roughly 890 Mt of steel going into buildings and infrastructure in one year, which is more than the other four uses combined. The shares come from one source and one year, so treat them as a snapshot, and quote the association’s own sector names if you cite them.

Farming, forestry, mining and defense are also big customers of iron and steel, but the World Steel Association’s published sector split does not show them separately. Their equipment sits inside the machinery and metal-products groups above.

Iron, steel and cast iron: what is the difference

Pure iron is soft and rusts quickly, so it is rarely used on its own. Almost everything sold as “iron” is an alloy with carbon. The dividing line is carbon content: steel holds less than 2% carbon, usually under 1%, and cast iron holds more than 2% (Machine Design). Steel can be rolled, forged and welded. Cast iron melts at a lower temperature than steel and flows well, so it is poured into complex shapes, but it cannot be rolled or forged.

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World crude steel production

Million tonnes per year

In practice there are three steps from rock to product. Ore (rock that holds iron minerals such as hematite and magnetite, covered in our guide to the four types of iron ore) is melted in a blast furnace to make pig iron, which is iron with a high carbon content. The pig iron is refined into steel, together with scrap. Or scrap steel alone is melted in an electric arc furnace.

The split between those routes matters for demand for ore. In 2025, about 69% of world crude steel was made in oxygen (blast-furnace) plants and about 30% in electric arc furnaces, according to the World Steel Association. The US figures are different: USGS reports that 47 companies ran 102 electric-arc minimills in the United States, and only two companies still ran integrated mills that make pig iron. The US used an estimated 57 million tonnes of scrap in 2025 against 21 million tonnes of pig iron produced (USGS, 2026 estimates). That is why a large part of the world’s “iron use” is a loop of steel being melted and used again, not new ore.

World crude steel output has been flat to slightly lower since 2020: 1,883 Mt in 2020, a peak of 1,963 Mt in 2021 and 1,849 Mt in 2025 (see the chart in this section).

Use 1: buildings and infrastructure

This is the largest use by a wide margin. Reinforcing bar (rebar) is the steel rod set inside concrete to carry tension. Beams and columns frame tall buildings, plate and sections make bridges, and pipe, rail, towers and storage tanks fill the rest. Steel is chosen because it is strong for its weight, can be welded on site and is recycled when a structure is pulled down.

USGS groups US steel shipments differently from the world totals above. For the United States, construction took an estimated 31% of net steel shipments in 2025, steel service centers and distributors (resellers that cut and sell steel on) 26%, automotive 15%, steel for converting and processing 11%, and all other uses 17%. Do not compare these line by line with the world shares, because the sector definitions are not the same. Both sources agree that construction is the largest end market.

Iron ore, steel and finished buildings sit in a long chain, and our post on how iron is used for modern infrastructure goes deeper on the construction side.

Use 2: transport, cars, trucks, ships and rail

Transport takes about 17% of world steel use: 12% for automotive and 5% for other transport such as ships, rail and aircraft parts (World Steel Association, 2025). Cars and trucks use sheet steel for bodies and doors, higher-strength steel for crash structures and frames, and iron castings for engine and brake parts. Ships are built almost entirely from steel plate, and railways use steel for track, wheels and wagons.

In the United States, automotive took 15% of steel shipments in 2025 (USGS). Vehicle makers are the customers that push steelmakers toward lighter, stronger grades, which is why the steel in a car today is not the steel in a car of the 1980s even though both are “iron” in the broad sense.

Use 3: machinery and mining equipment

Machinery is the third-largest use, at 16% of world steel use (World Steel Association, 2025). It covers the machines that make or move other things: farm tractors and combines, excavators, haul trucks, crushers and conveyors, pumps, compressors, gears and bearings. Parts that face abrasion, such as bucket teeth, crusher liners and grinding balls, use hard steel or white cast iron. Parts that take shock, such as shafts and frames, use tougher steel.

Mining is both a user and a supplier here. Mines buy large amounts of steel for equipment, rock bolts, support frames and pipe, and iron mines supply the ore that steelmakers start from. No public statistic gives the steel tonnage used by mining alone, so no figure is quoted for it.

Use 4: metal products and tools

Metal products make up 10% of world steel use (World Steel Association, 2025). The group covers fasteners (bolts, nails, screws), hand and power tools, wire and wire rope, containers and drums, cans made from tin-coated steel, furniture and shelving, and kitchen and hardware items. These products use a lot of steel in total but little in each item, which is why the group is large even though each product looks small.

Use 5: electrical equipment and appliances

Electrical equipment takes 3% and domestic appliances 2% of world steel use (World Steel Association, 2025). Electrical steel, a silicon steel with a controlled crystal structure, forms the laminated cores of motors, generators and transformers, where it carries a magnetic field efficiently. Fridges, washing machines and cookers use steel for casings and frames. The share is small, but the grade requirements are among the strictest of any steel product.

Uses of cast iron

Cast iron is a separate family with its own uses. Machine Design describes two common types. Gray iron holds its carbon as graphite flakes, which give high compressive strength and damp vibration well, so it is used for engine blocks, gears, flywheels, brake discs and drums, and machine bases. Ductile iron has a little magnesium added so the graphite forms small spheres, which makes it stronger and more shock-resistant than gray iron. It is used for parts such as crankshafts, heavy-duty gears and car door hinges (Machine Design).

White iron, which is very hard and brittle, is the third common type and is used where wear is the main problem. USGS reports that the ferrous castings industry uses most of the scrap that steel mills do not, and that about 107,000 people worked in US foundries in 2025 (estimate).

Uses of iron beyond steel

Steel is not the only use. Three smaller ones are worth knowing, because they are what many “uses of iron” questions actually mean.

• Iron oxide pigments. Iron oxides give red, yellow, brown and black colour to concrete and other construction products, paint and coatings, plastics and rubber, and they are used in ferrites (magnetic ceramics). USGS reports that US makers sold about 32,000 tonnes of finished natural and synthetic pigments in 2025, worth about 60 million US dollars, and that the US also imported about 180,000 tonnes (USGS, 2026).
• Other non-steel ore uses. USGS puts non-steel uses of US iron ore products at 2% of the total in 2025.
• The human body. Your body uses iron to make hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the rest of the body (MedlinePlus, US National Library of Medicine). This is a biological use of the element, supplied by food, not by the mined ore that feeds steel mills.

Two uses of iron or three uses of iron: short answers

Teachers and textbooks ask for a fixed number of uses. These answers match the data above.

• Two uses of iron: construction (rebar, beams, bridges) and machinery or transport (machines, vehicles, ships).
• Three uses of iron: construction, vehicles and machinery. Add tools and cast-iron parts such as engine blocks if you need a fourth.
• Five uses of iron: buildings and infrastructure, transport, machinery, metal products, and electrical equipment and appliances.
• Uses of iron ore: steelmaking (98% of US iron ore products in 2025) and small non-steel uses such as pigments.

Where the iron comes from: ore producers

World mines produced about 2.6 billion tonnes of usable iron ore in 2025, holding about 1.6 billion tonnes of iron, and world reserves are about 200 billion tonnes of crude ore (USGS, 2026). Australia and Brazil together mined about 860 million tonnes of the contained iron in 2025, a little over half of the world total. The United States produced about 1.4% of world ore.

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Iron contained in mined ore, selected producers

Million tonnes of iron; six selected producers

US production was 45.1 million tonnes of usable ore in 2024 and an estimated 38 million in 2025, shipped from eight open-pit mines in Michigan, Minnesota and Utah. The ore was valued at about 3.38 billion US dollars in 2025, down 25% from 2024. US ore is mostly low-grade taconite from the Lake Superior district, which needs crushing, magnetic separation and pelletizing before a steel mill can use it. Our guide to how bulk iron deposits are found and tested explains how those deposits are explored before any mine exists.

Earlier USGS editions reported about 48 million tonnes for 2024. The 2026 edition revised that year to 45.1 million tonnes, so use the newer figure.

▶ How AI is used in mineral exploration, where it helps and where it fails. · 4:37

Who makes the steel

China made about 980 million tonnes of the world’s roughly 1,900 million tonnes of raw steel in 2025, around half of the total (USGS, 2026 estimates). The United States made about 82 million tonnes, Japan 81, Russia 65 and South Korea 60, with Germany and Turkey close behind at 38 and 37. World pig iron output, the intermediate that blast furnaces make from ore, was about 1,300 million tonnes.

US raw steel output was 85.8 million tonnes in 2021, 80.5 in 2022, 81.4 in 2023, 79.5 in 2024 and an estimated 82 in 2025, worth about 149 billion US dollars. The country imported about 24 million tonnes of steel mill products in 2025 and exported about 7 million, and USGS puts net import reliance at 13% of apparent consumption. About 86,000 people worked in US iron and steel mills. Indiana made about 19% of US raw steel, followed by Ohio (8%), Texas (5%) and Pennsylvania (4%).

For a buyer, these numbers show that “iron use” is a story about steel mills and their customers. Ore miners sell to steel mills, and the mills sell to manufacturers and builders, so demand for ore follows demand for steel rather than any single product.

Iron ore and scrap prices

Iron ore is priced against a benchmark grade of 62% iron. Trading Economics showed 90.83 US dollars per tonne on 23 October 2026, down 6.5% over the month and 13.8% from a year earlier (Trading Economics). That is a quoted contract-for-difference price, not a transaction price, and it changes daily. Use it as a dated reference only.

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US average value of iron ore at the mine

US dollars per metric ton, average unit value reported by mines

USGS gives the average unit value reported by US mines, which is a different measure: 141.78 US dollars per tonne in 2021, 156.42 in 2022, 120.36 in 2023, 100.10 in 2024 and an estimated 89 in 2025 (USGS, 2026). The two are different measures, an annual mine-level average and a daily contract quote, so do not compare them directly. Scrap, the other raw material, averaged 314.85 US dollars per tonne in 2024 and an estimated 319 in 2025 for No. 1 heavy melting scrap delivered to US buyers (USGS, 2026).

Calculator: how much iron ore does a steel order need

Use the calculator below to turn a steel tonnage into the ore and scrap needed, and the ore cost. Every input is yours: the ore ratio and the price vary with ore grade and mill, so replace the examples with your supplier’s numbers.

How satellites help find iron ore

Iron ore deposits often show at the surface as iron-oxide staining, because iron minerals rust. Satellite images such as Sentinel-2 can show those rust-coloured areas, and they can show the clay minerals and faults around them. This gives explorers a way to rank where to sample first, before they spend on ground crews and drilling. A satellite screen is an exploration target map, not a resource estimate. Farmonaut offers satellite-based mineral detection for licence areas, and you can request a custom mining quote if you hold ground and want it screened.

▶ What a satellite map shows: iron-oxide rust, clay, silica and faults, and how to read them. · 4:18

Frequently asked questions

What are the 5 uses of iron?

By share of world steel use in 2025: buildings and infrastructure (52%), transport (17%), machinery (16%), metal products (10%) and electrical equipment and appliances (5%), using our grouping of the World Steel Association’s seven sector shares.

What are the two uses of iron?

The two largest uses are construction (rebar, beams, bridges) and machinery or transport (machines, vehicles, ships). Construction alone is about half of world steel use.

What are 3 uses of iron?

Construction, vehicles and machinery. Tools and cast-iron engine blocks are common extra examples.

What is iron ore used for?

Almost all of it goes into steel. USGS reports 98% of US iron ore products were used in steelmaking in 2025 and 2% in other uses, such as pigments.

What is the difference between iron and steel?

Both are mostly iron. Steel contains less than 2% carbon and can be rolled and welded. Cast iron contains more than 2% carbon, is poured into shapes and cannot be forged (Machine Design).

What is cast iron used for?

Gray iron is used for engine blocks, gears, flywheels, brake discs and machine bases. Ductile iron is used for crankshafts, heavy-duty gears and hinges.

Why does the body need iron?

Iron is used to make hemoglobin, the red-blood-cell protein that carries oxygen from the lungs around the body (MedlinePlus).

How much iron ore does the world mine?

About 2.6 billion tonnes of usable ore in 2025, holding about 1.6 billion tonnes of iron, with Australia and Brazil mining just over half of the iron (USGS, 2026).

How much does iron ore cost per tonne?

The 62% iron benchmark was 90.83 US dollars per tonne on 23 October 2026 (Trading Economics). The USGS average mine value for US ore was 100.10 US dollars per tonne in 2024 and an estimated 89 in 2025.

How much steel does the world use?

The World Steel Association counted 1,718.2 million tonnes of steel used in 2025, while crude steel production was 1,849 million tonnes.