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© Boardworks Ltd 20051 of 23 Resistant Materials Components These icons indicate that teacher’s notes or useful web addresses are available in the Notes.

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Presentation on theme: "© Boardworks Ltd 20051 of 23 Resistant Materials Components These icons indicate that teacher’s notes or useful web addresses are available in the Notes."— Presentation transcript:

1 © Boardworks Ltd 20051 of 23 Resistant Materials Components These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates that the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. © Boardworks Ltd 2005 1 of 23

2 © Boardworks Ltd 20052 of 23 Learning objectives © Boardworks Ltd 20052 of 23 Learning objectives To understand how fixings are used to join materials, and to be able to select an appropriate fixing for a given task. To understand how different nails and screws are used. To understand how rivets and bolts are used. To understand why and how hinges and handles are used.

3 © Boardworks Ltd 20053 of 23 It is unusual for a product to be made from only one piece of material. Usually you will have to join several components together to make a product. A range of fixings are available to complete a product, such as fasteners, fixings, hinges, springs, etc. What components do you think have been used to make this office table and chair? Components

4 © Boardworks Ltd 20054 of 23 They are used because they are: Nails are the most common forms of fixing used with wood. Nails are sold in standard forms by length and type. inexpensive quick to use easy to put in difficult to extract. round wireoval wirelost head panel pin cloutupholstery nail Nails

5 © Boardworks Ltd 20055 of 23 Types of nails

6 © Boardworks Ltd 20056 of 23 More grip is possible if the nails are hammered in at an angle – this is called dovetail nailing. When a nail is hammered into a piece of wood: the nail forces the fibres of the wood apart the lines of grain move and grip the nail if the nail is pulled, the fibres of wood grip the nail more firmly. Nails

7 © Boardworks Ltd 20057 of 23 If a nail is placed too close to the edge of a piece of wood, it will split. Oval nails should be used with the oval running along the grain to prevent splitting. Too many nails along the line of grain will also cause splitting. Problems with nails

8 © Boardworks Ltd 20058 of 23 gauge length type of head material. Screws are commonly used where the fixing may need to be temporary. They are used because they are: Screws are sold in standard forms by: strong easy to use easy to remove. twinfast screw countersunk round head raised head slotted phillips pozidrive Screws

9 © Boardworks Ltd 20059 of 23 Types of screw heads

10 © Boardworks Ltd 200510 of 23 1) Drill a clearance hole through the top piece of wood. 2) Drill a pilot hole in the other (or use a bradawl). 3) Countersink if appropriate. Joining two pieces of wood: Pilot and clearance holes

11 © Boardworks Ltd 200511 of 23 Brass screws are not as strong as steel and can break when being tightened. If joining hardwood, create the thread by using a steel screw first, take it out and then put in the brass screw. Chipboard screws are designed for joining fibrous chipboard and have a very coarse thread. Special screws

12 © Boardworks Ltd 200512 of 23 quick inexpensive traditional. snap head countersunk head flat head bifurcated rivet Rivets are used to join metal together permanently. Rivets are: Rivets

13 © Boardworks Ltd 200513 of 23 Pop rivets, also known as blind rivets, were designed to overcome the problem of riveting two pieces of material together when access was only possible from one side. Pop rivets are hollow with a steel pin through the centre. A hole is drilled through both pieces. The rivet is placed in a pop rivet gun and pushed through the two materials. The handle is pulled and the steel pin is pulled through the hollow rivet until it deforms the rivet and eventually snaps. steel pin rivet Pop rivets

14 © Boardworks Ltd 200514 of 23 Metals are often joined temporarily using nuts and bolts. Nuts and bolts allow you to assemble your product quickly and easily. They also allow for disassembly for maintenance and repair. Nut, bolt and washers The usual head for a bolt is a hexagon. This is tightened using a spanner, which may be open ended or ring. Nuts and bolts

15 © Boardworks Ltd 200515 of 23 There are many different types of nuts available. Hexagonal nuts can be tightened with normal spanners. Wing nuts can be tightened by hand. To prevent nuts from coming undone you may choose a nylock (a nylon insert inside a nut grips the thread) or a castellated nut with a split pin to prevent it coming undone. wingsquarehexagonalcastlenylock Nuts

16 © Boardworks Ltd 200516 of 23 Tightening hexagonal nuts and bolts against any surface will cause damage. Washers are used to protect the surfaces being clamped. Plain washers are inexpensive. Locking washers prevent nuts from coming undone in service. Tab washers ‘lock’ a nut in place to prevent it from coming loose. Spring washers are able to withstand vibrations. plainlocktabspring Washers

17 © Boardworks Ltd 200517 of 23 Large wooden structures may need strengthening. An inexpensive and convenient way of adding strength to the joints is to screw a metal plate to the wood. Angle plates and tee plates are made from mild steel. Strengthening plates

18 © Boardworks Ltd 200518 of 23 Knock-down fittings (KDF) create strong joints easily and quickly. They use temporary joints that can be taken apart and the furniture ‘knocked down’. Knock-down fittings A simple means of assembling knock-down furniture is to use nylon blocks with holes drilled in them.

19 © Boardworks Ltd 200519 of 23 Knock-down fittings using allen screws or threaded machine screws, which connect with threaded metal dowels, are used in assembling flat pack furniture such as bed frames and desks. Knock-down fittings

20 © Boardworks Ltd 200520 of 23 Many different types of hinges are available. Hinges allow doors to open and close easily, and support the door as it opens. One side of the hinge is screwed onto the door frame while the other is screwed to the door itself. Where would you expect to see hinges like the two pictured here? Hinges

21 © Boardworks Ltd 200521 of 23 Handles allow doors to be opened easily. There are many different types of knobs, pulls and handles. The handle you choose may depend on who the user is, and how much weight they will need to use the handle, as well as what the handle looks like. Where would you expect to see handles like the ones pictured here? Knobs, pulls, handles

22 © Boardworks Ltd 200522 of 23 Components quiz

23 © Boardworks Ltd 200523 of 23 Key points © Boardworks Ltd 200523 of 23 Key points Fixings are used to join different parts of a product. Nails are used to permanently join pieces of wood. Screws are used when fixings may need to be temporary. Rivets are used to join metals permanently. Nuts and bolts are used to temporarily join metals. Knock-down fittings create strong joints which can be easily taken apart. Hinges and handles come in many different types, and allow doors to open easily.


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