The main materials and alloys used in a workshop are mild steel, cast iron, tool steel, high speed steel (HSS) and tungsten carbide, plus the non-ferrous metals aluminium, copper and brass, and joining alloys such as solder and brazing filler. Mild steel is the default job material because it is cheap, soft and easy to cut, bend and weld; the harder steels and carbides are used for the tools that cut it.
This page follows the order a first-year B.Tech student meets the shops in workshop practice: fitting, smithy, welding, sheet metal and machine shop. It explains which material you will handle in each and why it was chosen. For the full family tree of ferrous and non-ferrous metals, see types of metal.
Materials and alloys used in workshop: quick reference
| Material | What it is | Where you meet it | Why it is chosen |
|---|---|---|---|
| Mild steel | Low carbon steel, up to about 0.25% C | Fitting, smithy, welding, machine shop jobs | Cheap, soft, easy to file, forge, weld and turn |
| Cast iron | Iron with about 2-4% C | Vice bodies, surface plates, lathe beds | Rigid, damps vibration, casts into complex shapes |
| High carbon / tool steel | About 0.6-1.5% C, hardened and tempered | Files, chisels, punches, hacksaw blades, taps | Hard enough to cut mild steel |
| High speed steel (HSS) | Tool steel alloyed with tungsten or molybdenum, chromium, vanadium | Lathe tools, drills, milling cutters | Keeps its edge when hot |
| Cemented carbide | Tungsten carbide grains bonded with cobalt | Brazed-tip and insert lathe tools | Much harder, allows higher cutting speeds |
| Galvanised steel sheet | Thin mild steel coated with zinc | Sheet metal shop | Bends easily, does not rust |
| Aluminium | Light non-ferrous metal | Sheet metal, machine shop practice jobs | Light, soft, machines fast |
| Copper | Pure non-ferrous metal | Soldering bits, electrical work, tube work | Conducts heat and electricity, very ductile |
| Brass | Copper-zinc alloy | Fittings, bushes, brazing rod | Machines cleanly, resists corrosion |
| Solder | Tin-based alloy (tin-lead or lead-free) | Sheet metal and electrical joints | Melts at low temperature |
| Brazing filler | Brass or silver-based alloy | Brazing in welding shop | Joins metals without melting them |
Fitting shop materials
In the fitting shop you file, saw, drill and tap a mild steel plate or bar into a finished job such as a square, V or dovetail fit. Mild steel is chosen because it is soft enough to hand-file in a two or three hour lab session, yet it holds a sharp edge and a measured size.
The tools are made of harder material. Files, hacksaw blades, chisels, scribers and centre punches are high carbon tool steel, hardened and tempered so they cut the mild steel instead of wearing out. The bench vice body is usually cast iron, and the marking-out surface plate is either cast iron or granite because both stay flat and stable.
Smithy (forging) shop materials
The smithy uses mild steel bar stock for jobs like a square rod, hook or chisel blank. When heated to a bright red it becomes soft enough to draw down, upset and bend with a hammer, and it does not crack easily because of its low carbon content.
The anvil face and hammers are hardened steel, and the tongs are mild steel. If a job calls for a cold chisel or punch, the blank is medium or high carbon steel, because it must be hardened afterwards by quenching and tempering. You can read how that works in heat treatment of steel.
Welding shop materials
Arc welding practice joints (butt, lap, T) are made on mild steel plate, typically a few millimetres thick, because low carbon steel welds without cracking and does not need preheating. The electrode is a mild steel core wire with a flux coating that shields the molten pool.
Aluminium is harder to weld. It conducts heat away quickly and has a tough oxide skin, so it is normally joined with MIG or TIG welding using an inert gas.
Brazing uses a filler of brass (copper-zinc) or a silver alloy. The filler melts above 450°C but below the melting point of the parts, so the base metal is never melted. It is used to join copper tubes, carbide tips to tool shanks and dissimilar metals. See brazing process and fillers.
Sheet metal shop materials
Sheet metal jobs such as trays, funnels and cylinders are made from thin galvanised iron (GI) sheet, which is really mild steel sheet with a zinc coating. It cuts with snips, folds cleanly and does not rust. Aluminium sheet and copper sheet are used where lightness or appearance matters.
Seams are often soldered. Soldering uses a filler that melts below 450°C: traditional tin-lead solder (such as 60/40) melts at roughly 183-190°C, and lead-free tin-silver-copper solders are now common. The soldering bit is copper because it holds and passes heat well. Flux cleans the joint so the solder wets it.
Machine shop materials
On the lathe, shaper and milling machine, the job is usually a mild steel round bar, sometimes aluminium or brass for faster, cleaner cuts. Brass produces small broken chips and a bright finish, which makes it popular for fittings and bushes.
The cutting tools are what change here:
- High speed steel (HSS): the traditional 18-4-1 grade has 18% tungsten, 4% chromium and 1% vanadium. HSS keeps its hardness when the tool tip gets hot, which plain carbon tool steel cannot do. Students grind their own single-point lathe tools from HSS blanks, and most drills and milling cutters are HSS.
- Cemented carbide: tungsten carbide particles bonded with cobalt. Harder and more heat resistant than HSS, so it cuts at several times the speed, but it is brittle and cannot be ground on an ordinary bench grinder. Used as brazed tips or clamped inserts.
The machines themselves have cast iron beds and columns because cast iron is rigid and absorbs vibration, which gives a better surface finish.
Why these materials? The selection logic
- Job material is soft and cheap (mild steel, aluminium, brass) so beginners can finish it with hand tools or basic machines.
- Tool material is always harder than the job (tool steel, HSS, carbide).
- Machine structures need rigidity and damping (cast iron).
- Joining alloys melt below the parts (solder below 450°C, brazing filler above it, welding melts the base metal itself).
- Corrosion resistance where it shows or gets wet (GI sheet, copper, brass).
The terms used here, such as hardness, ductility and malleability, are defined in mechanical properties of materials. More on alloys and grade data is available from ASM International – Materials Information.
FAQs
Which material is most used in the workshop?
Mild steel. It is the job material in fitting, smithy, welding and most machine shop exercises because it is cheap, soft and easy to file, forge, weld and machine.
Why is cast iron used for machine beds and vices?
Cast iron is rigid, stable and damps vibration well, and it can be cast into complex shapes. That keeps machines accurate and gives a better surface finish on the job.
What is the difference between HSS and carbon tool steel?
Both are hard steels, but HSS contains tungsten or molybdenum, chromium and vanadium, so it keeps its hardness at high cutting temperatures. Plain carbon tool steel softens when it gets hot, so it is used for hand tools like files and chisels.
What is the difference between soldering and brazing fillers?
Soldering fillers melt below 450°C and are mostly tin alloys. Brazing fillers melt above 450°C and are brass or silver alloys. Neither melts the base metal, unlike welding.
Which alloys are commonly used in workshops?
Steel (iron-carbon), brass (copper-zinc), bronze (copper-tin), solder (tin-lead or tin-silver-copper), HSS and aluminium alloys.