sheet metal shop.pptx

Mechanic

1. SHEET METAL SHOP

2. INTRODUCTION

3. The sheet metal shop is very important for every engineering concern. It deals with the working of metal sheets. It requires through knowledge of projective geometry, the development of surfaces because the laying of the pattern and cutting of metal sheets according to size and shapes initially depends upon the knowledge of the workman. The various operations performed in a sheet metal shop are marking cutting, shearing, bending & joining etc.

4. TOOLS AND EQUIPMENTS USED IN SHEET METAL SHOP The various sheet metal tools inside a workshop lab can be classified in to three categories: A) Hand Tools B) Bench Tools C) Machine Tools

5. hand tools They are basic working tools which are easily handled by the common worker and without much effort give the desired output. On broad classification the hand tools are described below: Measuring and checking tools. Marking tools Cutting tools Striking tools General tools

6. MEASURING AND CHECKING TOOLS STEEL RULE or SCALE Steel rule is a flat, rectangular graduated tenthly stainless steel instrument, used for measuring a dimension of various object for marking and drawing purposes on the gap. The straightness provides the accurate distance between two points. It has been divided according to unit and sizes. According to Unit:- Millimetre, Centimetre, Meter , Metric Steel Tape, Inch. According to size :-15 Cm, 30 Cm, 100 Cm Size in inch i ) 6 inch ii) 12 inch iii) 24 inch

7. L – SQUARE Its one side is 24 inch or 60 cm, another is 12 inch or 30 cm. where its both sides meet they make 90 angle. It is used to check the correctness of right angle. It is made up of hard steel. TRY SQUARE It is checking tool. It has two parts. Blade Stock

8. BLADE:- It has graduation in inches and cm. It is used to check the dimension and right of any work piece. It is also used to check the flatness of any surface. STOCK:- Usually it is made of steel or wood which is used to hold the instrument. WIRE GAUGE The wire gauge is used to check the diameter of wires or thickness of sheet metal. The commonly used wire gauge is Imperia1 Standard Wire Gauge (known as SWG ). It has slots to indicate different width sizes. The most common wire gauge used in sheet metal has 21 slots with gauges varying from 4 to 24.

9. CALIPERS They are mostly used for measuring and marking purposes. They are of many type: Outside caliper:- It is used to take the outer measurement. Inside caliper :- It is used to take inner measurement. Jenny caliper:- It is also know as odd leg or hermaphrodite. It is used to draw parallel line on rectangular or square work piece. It is also used to locate the center of any round work piece. Outside caliper Inside caliper Jenny caliper

10. MARKING TOOLS SCRIBER It is a piece of hardened steel wire about 150 to 200 mm long, 3 to 5 mm diameter with pointed one or both ends like to needle. It is held like a pencil to scratch or strive straight line on metal. DIVIDER It has two pointed vertical legs adjusted with spring points at top. It is used to draw an arc circle on the metal sheet.

11. TRAMMEL It is used alternative of divider, particularly in large work. Essentially it consist of two adjustable vertical legs of trammel points mounted on a common rod called beam, which can be brought closer or opened out as desired. It is used beyond the limit of divider to draw a big arc or circle. It is also called a beam compass. PUNCH It is used for marking out work, locating centre and punching work. They are made up of steel.

12. TYPES OF PUNCH Centre Punch Pin Punch Prick Punch Dot Punch Hollow Punch

13. CUTING TOOLS SNIPS :- It is also known as hand shear. It has pair of cutting blades like scissors. It is used to cut a thing and soft sheet. They are two types. i ) Straight snips ii) Bent or curved snips STRAIGHT SNIPS :- They have straight cutting blades for straight line cutting. BENT or CURVED SNIPS :- They have curved cutting blades to make a circular cuts.

14. CHISEL It is cutting tool made of hexagon or octagon cast steel bar or high carbon steel bar. TYPE OF CHISEL Flat chisel Cross cut chisel Diamond point chisel Round nose chisel Side cut chisel Cow mouth chisel

15. STRIKING TOOLS HAMMERS:- The hammer is a striking tool. It has a handle and a head. Ball peen hammer Cross peen hammer Square hammer Round Mallet hammer Rectangular Mallet hammer

16. GENERAL TOOLS Soldering iron File Plier Screw Driver MACHINE TOOLS :- Bench Shearing Machine Fly Press Machine

17. SHEARING MACHINE The simple shearing machine is used to shear the sheet metal using a compound lever. The shearing machine has fixed bottom blade and a top shearing blade which is operated by a lever. It is used to shear metal plates which can’t be cut or trim by snip .

18. FLY PRESS MACHINE A Fly Press is a machine tool used to shape sheet metal by deforming it or cutting it with punches and dies. If used for piercing holes in sheet metal work, the fly press tool itself consists of a punch and clearance die, into which it just fits.

19. BENCH & SUPPORTING TOOLS The tools which are first fitted on bench and then are used bench tool s. STRAIGHT EDGE It is also known as bending bar it has barrel edge. It is used to bend the sheet. A longitudinal groove is provided with it on back side for making channels. It is made up of cast steel . SUPPORTING TOOLS They are following type: Rail line piece. Piece of mild steel round bar Piece of mild steel square bar Piece of mild steel plate.

20. Rail line piece. Piece of mild steel round bar. Piece of mild steel square bar Piece of mild steel plate.

21. TYPE OF BENCH STAKE FUNNEL STAKE HALF MOON STAKE BICK IRON STAKE HATCHET STAKE PIPE STAKE GROOVING STAKE ANVIL STAKE

22. SHEET Sheet are made by pressing the hot section in sheet rolling machine. The rolled sheet become too hard hardness in removed by annealing. METAL USED IN SHEET METAL A fairly large variety of metals are used in the forms of sheet and plates.

23. GAUGE NUMBER Corresponds to the definite thickness of sheet these number can be know by using thickness gauge or thickness wire gauge. The thickness of sheet varies inversely with higher gauge number, smaller thickness and vice versa upto 10 gauge number the object is known as sheet. Less than 10 gauge number it is known as bar. TYPE OF SHEET 1. Black iron sheet 2. Galvanized iron sheet 3. Copper sheet 4. Aluminum sheet 5. Stainless sheet 6. Tin coated sheet 7. Brass sheet

24. SHEET METAL OPERATIONS MARKING Development drawing or marking is done over the sheet before proceeding to another operation. This gives it true shapes and reduce wastage of sheet. LAYING OUT It means the operation of the developments of the surface of the components on the sheet together with added allowances for operating, overlapping , bending & joining etc. which when cut of blank and folded and joint will give the required component. Such a layout when made from the sheet is called pattern and processed as pattern layout.

25. CUTTING AND SHEARING The word cutting is normally used when the sheet metal is cut by means of chisel and hammer mainly. The term shearing stands for cutting of the sheet metal by two parallel cutting edge moving in opposite direction. This can either be done mainly by using hand shear or snips or by means of a machine called shearing machines. The operation is then called machine or machines. NOTCHING When the pattern is drawn the necessary allowance are given on the sheet and corners are cut to avoid cracks while bending is known as notching.

26. EDGE FORMING The edge of the metal products are formed and folded to ensure safety of hands while handing these products and to provide safeness to the product in order to retain their shapes while handling. HEMMING There are two types of hemming:- Single hemming : Folding of edges or ends of the sheet four to ten times of the thickness of the sheet if the dimensions are not given. Double hemming : The fold is given doubled to strengthened the edges of the model.

27. HEMMING SINGLE HEMMING DOUBLE HEMMING

28. WIRING OR WIRED EDGE When very strong edges are needed they are reinforced by inserting a metal wore or rod and then forming edges by curling the edges of sheet metal around it. This is not only increases the strengthens of the edges but also to improve its appearance. There are two types of wiring. True wiring False wiring SWAGING Making a groove in sheet metal in round job by swaging machine is called swaging. BENDING It is same as swaging but done away from the edge, it is done by bending machine giving concave shape on the sheet.

29. HALLOWING Giving concave shape or hallowing in sheet as in mud guard. RASING It is a process to give concavc shape over the body as halmet. NIBBLING It is a process of continuous cutting along a contour which may be straight or irregular profile. Machines use in this operation are called nibblers. HAND FORMING It means shaping or bending of sheet in their dimensions in order to give it a desired shape or sizes of final product. SOLDERING It is method of joining two metals without causing it to melt and destroy the metal sheet. It is method of joining two metals by a third metal of soft metal by solder in molten state.

30. SHEET METAL JOINTS There are three type of joints: 1. Mechanical joints 2. Metallic joints 3. Riveted joints

31. MECHANICAL JOINTS They are also known as folded joints or seam joints or without medium. They are classified into – a. Lap joints b. Locked grooved joints c. Panned down joints d. Knocked up joints f. Corner joints g. Cap joints

32. METALLIC JOINTS This includes welding brazing hard and soft soldering. SOFT SOLDERING Soft soldering includes in following materials: BIT It is mainly of copper or iron. SOFT SOLDER It is a non ferrous alloy of tin and lead in some instances small percentage of antimony are included. Bismuth is included sometimes for lowering the melting point.

33. SOLDERING FLUX: There ate two type of fluxes: Corrosive flux: which are alcohol salt or acid bases. Non-corrosive flux: which are non acid bases eg : borax, rosin, fat. RIVETED JOINTS It is permanent fastening method. It is largely used in the manufacturing of boilers, pressure vessel, coach ,furnace bodies, steel bridges and different type of steel structures.

34. RIVET It is a parallel shank metallic pin with head at one of its end. It has two pared. They are shank and head.

35. TYPE OF RIVET Shank is common part of rivet. So rivet are classified according to shape of its head. 1. Flat head rivet 2. Round or cap head rivet 3. Conical head rivet 4. Half conical head rivet 5. Counter sunk head rivet 6. Half counter sunk head rivet 7. Pan head rivet 8. Split rivet.

36. PRECAUTIONS :- Marking should be done correctly. Cutting should be done efficiently to avoid flow in measurement. While soldering saddening bit should not over heated. The flux should be spread efficiently.

37. Job No. 1 Object :- To make and development of Tray as per as given drawing . Material Required:- G.I. Sheet 30 gauge [ size :- 180 x 145 mm] Tools Required :- Steel Rule L- Square Try Square Wire Gauge Scriber Snip Square Hammer Mallet Hammer Plier File Straight Edge

38. Stakes Soldering Iron Theory :- What is sheet metal shop and its uses. Procedure :- Write Point Wise

39. RESULTS :- ALL DIMENSIONS ARE IN MM