Learning outcomes (what you will be able to do)

• Identify and outline: distinction between ferrous & non‑ferrous metals; properties of metals; production of iron from ore; forms & means of material supply in a workshop; everyday uses of metals.
• Distinguish ferrous from non‑ferrous metals in material selection.
• Explain common properties of metals found in a metal workshop.
• Describe simply how iron is produced from its ore.
• List common forms (bars, sheets, rods) and how materials are supplied to workshops in Kenya.
• Appreciate the uses of ferrous and non‑ferrous metals in daily life (Kenyan examples).

1. Distinction: Ferrous vs Non‑ferrous metals

How to tell them apart (simple tests): use a magnet (sticks = ferrous), look for rust after leaving in wet air (rust = ferrous), check weight (aluminium is light), or ask the supplier/markings.

2. Properties of metals (what to look for in the workshop)

• Hardness: resistance to indentation or wear. Hard metals are used where surfaces must not scratch easily (e.g., tool steels).
• Toughness: ability to absorb energy without breaking (important for structural parts).
• Malleability: metal can be hammered/thinly spread (e.g., copper, aluminium).
• Ductility: can be drawn into wire (copper is very ductile).
• Conductivity: electrical and thermal; copper and aluminium are good conductors.
• Density: how heavy for a given volume — aluminium is low density (light), steel is higher.
• Corrosion resistance: how well the metal resists rust — stainless steel, aluminium, copper and zinc resist corrosion better than ordinary iron.
• Melting point: affects welding and casting choices (steel melts at higher temperature than aluminium).

Application tip: choose a metal based on the needed property — e.g., use copper for wires (conductivity), steel for beams (strength), aluminium for light frames.

3. Production of iron from ore (simple, class‑level explanation)

The usual industrial method (blast furnace) in simple steps:

1. Mining the ore: iron ore (mainly hematite or magnetite) is extracted from mines.
2. Preparation: crushing and concentrating the ore to increase iron content.
3. Charging the blast furnace: layers of iron ore, coke (carbon fuel), and limestone are loaded into the furnace.
4. Smelting: hot air is blown in; coke burns producing CO which reduces iron oxide to molten iron. Limestone removes impurities as slag.
5. Collecting products: molten iron (pig iron) is tapped from the bottom; slag floats on top and is removed.
6. Refining: pig iron is further refined (basic oxygen or electric furnace) to make steel or cast iron with controlled carbon levels.

Classroom simplification: show a labelled diagram or animation of a blast furnace, or do a demonstration with clay ore models to explain layers and flows. Emphasise that this is large‑scale industrial work; small workshops buy processed metal (steel bars, sheets).

4. Forms and means of material supply in a workshop

Common forms of metal supplied to workshops in Kenya:

• Sheets / Plates: thin metal sheets (mabati/steel sheets) used for roofing, boxes and panels.
• Bars / Rods / Rebars: round or square bars used for frames, supports and fabrication.
• Coils / Strips: rolled steel or aluminium used for bending and pressing.
• Pipes / Tubes: hollow sections for structures, plumbing and handrails.
• Wire: for binding, fencing and electrical use (copper wire).
• Castings: prefabricated parts (gear housings, pulleys).

How materials are supplied: local hardware stores, steel merchants (e.g., in Nairobi’s industrial areas), building suppliers, and direct from factories. Materials may be sold by weight (kg), length (m), or per piece.

Workshop practice: keep a simple stock list: item, size, quantity, supplier, date received — helps avoid delays on projects.

5. Use of ferrous and non‑ferrous metals in daily life (Kenyan examples)

Local note: using the right metal increases life of the product — e.g., galvanised nails for outdoor work, aluminium for small portable cookware.

6. Simple classroom activities and suggested learning experiences (safe, hands‑on)

1. Magnet test station — give students a selection of metal samples (nail, coin, aluminium can, copper wire). Ask them to test with a magnet, record which are magnetic, and classify as ferrous/non‑ferrous.
2. Rust experiment (observation) — place identical iron nails in three jars: (A) dry air, (B) water, (C) salt water. Observe over days and record rusting. Safety: do not taste or handle salt water jars; dispose responsibly.
3. Conductivity simple test — using a small 3V battery, bulb and clips, test which metals make the bulb light. Use copper and aluminium pieces (supervise closely).
4. Bending/drawing test — give short lengths of copper wire and steel wire; bend and note ductility and malleability. Discuss why copper is used for wires.
5. Field visit or virtual tour — visit a local hardware shop or small fabrication workshop. Identify different forms of metal, ask about suppliers and how materials are priced (per kg, per meter).
6. Design brief — small group project to design and sketch a simple product (e.g., a jiko stand or a school gate model). Decide which metals to use and justify choices based on properties.

Safety notes: always wear eye protection when cutting or hammering, gloves when handling sharp sheets, and never heat metals without teacher supervision.

7. Quick summary & useful tips

• Ferrous = contains iron, magnetic, rusts easily. Non‑ferrous = no iron, often non‑magnetic, more corrosion resistant.
• Choose metals using properties: strength, weight, conductivity, corrosion resistance, cost.
• Most schools and workshops buy processed metals (bars, sheets) rather than raw ore.
• Simple tests (magnet, visual rust, weight) help identify metal type quickly.

8. Short assessment questions (for practice)

1. List three differences between ferrous and non‑ferrous metals.
2. Why is aluminium often chosen for cooking pots instead of steel?
3. Describe the main steps in the production of iron from its ore (brief).
4. Name four common forms in which metal is supplied to a workshop.
5. Give two Kenyan examples where ferrous metals are used and two where non‑ferrous metals are used.

Teacher tip: use group presentations for answers and check practical tests (magnet, conductivity) as evidence of learning.