Workshop Practice (GE102)
Reference manual for the sheet metal experiment
Exercise-1
● Objective(s): To make dust pan for the given drawing by using give GI sheet.
● Introduction: Sheet metal work is working with metal sheets from 16 – 30
gauge, using hand tools and simple machines. By marking, cutting, forming in to
shape and joining to fabricate many domestic utility items, machine covers,
hoppers, guards, tanks, stacks, duct work, pipes, bend, boxes, etc. common
metals used in sheet metal work are black iron, galvanized iron, stainless steel,
copper, brass, zinc, aluminum, tin plate and lead. The material, which is used in
workshop, is galvanized iron. It is zinc coated hence it is known as galvanized
iron sheet. This sheet can withstand contact with water and exposure to
atmosphere. Sheet metal work is the process of metalworking that forms new
products from various types of sheet metal into desired shape.
● Materials Required: - Galvanized iron (GI) sheet Gauge 25.
● Apparatus and tool required: -
(1) For sheet cutting: - Snip (straight snip, bent snip) etc.
A snip is a hand shear used to cut thin sheets of gauge size number 20 or
above. It works like ordinary scissors. There are several types and sizes of
snips available to cut along straight lines or curved lines. These snips are
used for cutting thin sheets.
(2) Measuring and marking device: - (Vernier caliper, Steel rule, Try square,
Marker pen, Sheet Metal gauge, Scriber and Punches etc.)
(3) Forming Tools: - Stakes/bench vice, Mallets are soft hammers etc.
(4) Joining tools: - Rivet, Ball pen hammer, Rivet gun, drill punch etc.
● Procedure: -
1. Clean the given sheet with cotton waste.
2. The size of the given sheet is checked with the steel rule.
3. Flatten the surface of the given sheet with wooden mallet.
4. Check the G.I. Sheet for dimensions and remove extra material, if any.
5. Shear a rectangular piece of sheet outer rough cutting.
6. Mark all the measuring lines on the given sheet with scriber.
7. Cut the given sheet with straight snips as required.
8. Fold the given sheet by using stakes and hammers to the required shape.
9. Join the handle by riveting methods
● Precautions:
(1) Must wear proper safety shoes, safety gloves and apron.
(2) Follow proper safety protocol during the operation.
(3) For marking purpose use scriber only. Do not use pencil or pen.
(4) Sufficient care is to be taken while cutting and folding of G.I. sheet.
(5) Remove the waste pieces immediately from the work place.
(6) Take care of yourself and your colleagues while cutting and striking.
● Difficulties that may arise
(Write the technical difficulties that you think may arise during the experiment)
● Result: - Dust tray is prepared as per the required dimensions.
● Conclusion:
(What new knowledge(s) one can learn by doing this experiment.
Write short not on application of sheet metal working.
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Exercise-2
Aim
To make a Tray of square shape from given G.I. sheet.
Tools required
Steel rule, Scriber, Rubber mallet, Nylon mallet, wood mallet, Bevel
protractor, Standard wire gauge/ Sheet thickness Measuring gauge, Snips/Tin cutter,
Stakes, Rivet Gun, Hand Punch, Ball Peen Hammer, Cross peen hammer.
Machine used
Sheet bending machine and shearing machine.
Material used
Galvanized Iron (G.I) sheet of 24 gauge and rivets (5mm).
Sequence of operations
1. cut to an area sufficient for making the box.
2. Check the dimensions of the given sheet using steel rule and thickness
measuring gauge.
3. Draw the development of the tray on G.I. sheet and obtain various
dimensions. Provide allowances for edge folding and also for flap. Mark the obtained
dimensions on the given work sheet surface using scriber.
4. Cut and remove the unwanted / excess materials using tin cutter.
5. Hold the work piece suitably in a sheet folding machine and bend the sheet
along the edges of the box and also using Stakes and Mallet.
6. Complete bending process of the work piece.
7.Punch the holes at respective position by hand punch machine.
7. Fold the flaps to the inner surface of the wall for riveting and rivet it by
rivet gun.
8. Complete edge folding along the open edges of the box to avoid sharp
edges.
9. Complete trimming and finishing operations to ensure accuracy and safety.
Result:
The Tray is thus made by following the above sequence of operations
