Basic metal types for small DIY jobs

Understanding Common DIY Metals

For small repairs, bracket-making, or custom fixes, hardware stores sell a variety of metal sheets, tubes, and flat bars. Choosing the wrong metal can lead to parts rusting away, failing under load, or ruining your drill bits.

1. Mild Steel

Steel is an alloy of iron and carbon. “Mild” steel is the most common and affordable type found in DIY stores.

• Properties: It is very strong, rigid, and magnetic.
• The Problem: It rusts quickly when exposed to moisture. If you use mild steel outdoors or in a bathroom, it must be thoroughly primed and painted, or you must buy steel that has been “galvanised” (coated in a protective layer of zinc).
• Working with it: Cutting and drilling steel requires High-Speed Steel (HSS) or Cobalt drill bits and a hacksaw. Always use a few drops of oil when drilling to prevent the bit from overheating and losing its temper.

2. Stainless Steel

Stainless steel contains chromium, which prevents it from rusting.

• Properties: It is ideal for outdoor brackets, marine environments, and kitchen splashbacks.
• The Problem: It is significantly harder and more expensive than mild steel.
• Working with it: Drilling stainless steel is notoriously difficult for beginners. It “work-hardens” rapidly; if your drill bit spins without cutting, the steel surface becomes incredibly hard, making further drilling almost impossible. Use high pressure, low RPMs, and plenty of cutting fluid.

3. Aluminium

Aluminium is a highly versatile metal, commonly sold as extruded angles, tubes, and flat bars.

• Properties: It is roughly one-third the weight of steel, completely non-magnetic, and does not rust (it oxidises to form a protective dull grey layer).
• Working with it: It is a soft metal, making it very easy to cut with a standard hacksaw and drill with regular bits. However, its softness means it can bend easily under load, and screws threaded into it can strip easily.

4. Brass and Copper

These are “yellow metals” primarily used for decorative purposes, plumbing, and electrical work.

• Properties: They do not rust, but they will tarnish (turn brown or green) over time unless polished and lacquered.
• Working with them: They are very soft and extremely easy to machine, cut, and drill.

Managing Sharp Edges

When you cut or drill any metal, it leaves a raised, jagged edge called a burr. These burrs are razor-sharp. Always keep a metal file or sandpaper nearby and immediately file the edges smooth (deburring) to prevent serious cuts. Wear thick gloves when handling sheet metal.