Sheet Metal work
- Sheet metal work involves cutting, shaping, and joining thin metal sheets to create various structures, components, and products. It is widely used in HVAC systems, automotive industries, aerospace, and manufacturing.
Hand Tools Used in Sheet Metal Work
| Tool Name | Function | Application |
|---|---|---|
| Steel Rule | Measuring sheet metal | Layout marking |
| Scriber | Marking guidelines on metal | Used for precision cutting |
| Divider | Marking circles and arcs | Layout preparation |
| Snips (Straight, Left, Right) | Cutting sheet metal | Used for shaping metal sheets |
| Mallet & Hammer | Bending & shaping | Used in forming sheet metal |
| Punch (Centre, Hole, Prick, Letter) | Marking & making holes | Used in riveting and layout |
| Files | Smoothening edges | Used for fine finishing |
| Grooving & Beading Tools | Strengthening sheet edges | Used in ductwork & roofing |
Power Tools Used in Sheet Metal Work
| Power Tool | Function | Application |
|---|---|---|
| Bench Shears | Cutting thick sheet metal | Used in industrial cutting |
| Nibbler | Precise sheet metal cutting | Used for making intricate shapes |
| Drilling Machine | Drilling holes | Used in assembling components |
| Angle Grinder | Cutting, grinding, polishing | Used for shaping & finishing |
| Welding Machine | Joining metal sheets | Used in fabrication |
- Care & Maintenance of Tools
- Keep tools clean & rust-free.
- Store in a dry, organized toolbox.
- Sharpen cutting tools (snips, chisels) regularly.
- Inspect electrical tools for worn-out wires before use.
Types of Sheet Metal Joints
| Joint Type | Description | Common Applications |
|---|---|---|
| Lap Joint | Overlapping two sheets and joining them | Used in ducts, pipes |
| Grooved Seam | Sheets folded into grooves and locked | Used in HVAC ducts, roofing |
| Single & Double Seam | Folded seams for strength | Used in cylindrical parts |
| Butt Joint | Sheets joined edge-to-edge | Used in welding applications |
| Flange Joint | Sheets bent and joined for reinforcement | Used in industrial sheet metal work |
| Corner Joint | Right-angled sheets joined | Used in enclosures, boxes |
Types of Rivets & Their Applications
| Rivet Type | Function | Common Uses |
|---|---|---|
| Solid Rivet | Strong permanent joint | Used in aircraft, ships |
| Blind Rivet (Pop Rivet) | Can be installed from one side | Used in automotive panels |
| Tubular Rivet | Lightweight connection | Used in lightweight structures |
| Flush Rivet | Smooth finish | Used in aerospace |
| Drive Rivet | Hammered into place | Used in fast assembly work |
- Riveting Process
-
- Mark & drill holes on sheets.
- Insert rivet through the hole.
- Hammer or use a rivet gun to secure it.
- Ensure tight fit for strength.
- Advantages of Riveting
- ✔ Strong, permanent joint
✔ Withstands vibrations
✔ Used where welding is difficult
- ✔ Strong, permanent joint
- 5. Uses of Sheet Metal Work
- ✔ HVAC Ducts & Ventilation
✔ Roofing & Guttering
✔ Automotive Bodies
✔ Aircraft & Shipbuilding
✔ Kitchen Appliances & Furniture
- ✔ HVAC Ducts & Ventilation
- Fasteners – join two or more objects together, either permanently (rivets, welding) or temporarily (bolts, screws, nuts).
- Types of Fasteners
- (i) Permanent Fasteners
- These fasteners create a non-removable joint, meaning they cannot be removed without damaging the joint.
- Welding (Fusion, Spot Welding, Thermit Welding)
- Adhesives (Epoxy, Resins, Glues)
- (ii) Temporary Fasteners
- These fasteners allow for easy removal and reassembly without damaging the components.
- Rivets (Solid, Blind, Tubular, Split)
- Bolts & Nuts
- Screws & Washers
- Pins & Clips
- Anchors & Inserts
- These fasteners allow for easy removal and reassembly without damaging the components.
- (i) Permanent Fasteners
- Rivets rivet is a mechanical fastener consisting of a head and a shank. When installed, the shank is deformed or expanded to create a joint.
- Types of Rivets
- Solid Rivets
- Blind Rivets (Pop Rivets)
- Tubular Rivets
- Split Rivets
- Bolts: Have external threads and require a nut to secure the joint.
- Nuts: Internal threads that mate with a bolt to provide strong clamping force.
- Screws – Have external threads and do not require a nut.
- Washers – Used with bolts and nuts to distribute load and prevent loosening.
Sheet Comparison Table
| Sheet Type | Material | Corrosion Resistance | Strength | Weight | Common Uses |
|---|---|---|---|---|---|
| GI Sheet | Zinc-coated steel | Moderate | High | Medium | Roofing, sheds, ducting |
| Galvalume Sheet | Al-Zn coated steel | High | High | Medium | Roofing, car bodies |
| MS Sheet | Mild Steel | Low (needs coating) | High | Heavy | Structural, fabrication |
| SS Sheet | Stainless Steel | Very High | Very High | Heavy | Food industry, hospitals |
| Aluminum Sheet | Aluminum | Very High | Medium | Light | Aircraft, packaging |
| Corrugated Sheet | Metal or plastic | Depends on material | High | Medium | Roofing, fencing |
| Polycarbonate Sheet | Plastic | High | Medium | Light | Skylights, greenhouses |
| Acrylic Sheet | Plastic | High | Low | Light | Display cases, signage |
| FRP Sheet | Fiberglass | Very High | High | Light | Chemical plants, cladding |
- SWG (Standard Wire Gauge)
- thickness of a sheet is measured
- Used in India & UK for sheet metal thickness.
- Lower gauge = Thicker sheet
- Higher gauge number = Thinner sheet
- 16 SWG = 1.6 mm
- 20 SWG = 1 mm
- Square Stake – supporting tool used in sheet metal forming and shaping.
- Shape: Square top with a long stem for securing into a workbench or stake holder.
- Material: Hardened steel (to resist wear and deformation).
- Uses:
- Bending and shaping sheet metal.
- Creating sharp corners and precise edges.
- Supporting hammering and forming without damage.
- Mallet – A mallet is a hammer-like tool used in sheet metal work to shape and form metal without damaging the surface.
- Uses:
- Shaping and forming metal on stakes (like the square stake).
- Flattening and bending without damaging the surface.
- Used with stakes to create specific shapes.
