Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
96 Cards in this Set
- Front
- Back
|
Two types of timber
|
Hardwoods and Softwoods
|
|
|
Hardwoods are from...
|
Deciduous tress
|
|
|
Softwoods are from...
|
Coniferous trees
|
|
|
Name four wood defects
|
Warping, bowing, cupping, splitting or knots
|
|
|
Properties of hardwoods
|
More fibrous = greater mechanical strength and hardness
More expensive - because they take a longer time to grow |
|
|
Properties of softwoods
|
Made up of tube like cells - less dense, more prone to water damage
Can be resinous - Pine is VERY resinous |
|
|
Growth and Production of woods
|
Trees girth increases with height. Summer growth responsible for mechanical strength. Variation in look of cells = annual rings. Tree is felled then ready for seasoning. Once timber has dried out is cut into common shapes and sizes and can be sold.
|
|
|
Everything about oak...
|
Hardwood, tough, hard, durable
Used for furniture and veneers Finishes well Contains an acid that corrodes steel |
|
|
Everything about mahogany...
|
Hardwood, durable, medium density
Indoor furniture and woodwork Finishes well and is easy to work Prone to warping |
|
|
Everything about beech...
|
Hardwood, hard, tough
Toys and kitchen utensils Turns and finishes well Warping |
|
|
Everything about ash...
|
Hardwood, tough, flexible, good elasticity
Ladders, laminated furniture Flexible Can splinter |
|
|
Everything about pine...
|
Softwood, lightweight
Floorboards, toys Grows quickly, sustainable, nice colour and grain Warping and knots |
|
|
Advantages of manufactured boards
|
Available in large, flat sheets - not so much to join
Good dimensional stability Can be decorated - veneers, paint Flexible and easy to bend for laminating Wood wast can be used for chipboard and MDF |
|
|
Disadvantages of manufactured boards
|
Sharp tools needed as easily blunted
Thin sheets will bow if unsupported Difficult to join using traditional construction methods Sanding can produce hazardous dust particles Edges have to be treated |
|
|
How is plywood made...
|
Made of veneers, odd number of individual plies glued together at 90 degree angles to each other using synthetic resin and then compressed using a heat press.
|
|
|
Everything about plywood...
|
Very strong in all directions, resistant to splitting
Boat building Large sheets, tick sheets won't warp |
|
|
Everything about chipboard...
|
No grain patterns, made from waste products of wood bonded together using strong resins
Strong in all directions Not very water resistant, will chip on edges if unprotected |
|
|
Everything about MDF...
|
Good surface finish that can be veneered or painted
Dense, stable to changing conditions Will break down and absorb water if it gets very wet |
|
|
Everything about hardboard...
|
One side textured one side smooth
Made from compressed fibres soaked in resin before compressing Cheap Not strong as has no grain |
|
|
What are ferrous metals...
|
Contain iron, will rust, usually magnetic
|
|
|
Everything about mild steel...
|
Tough, malleable, magnetic
Structural girders Easy to join, cheap, recyclable Will oxidise if unprotected |
|
|
Everything about stainless steel...
|
Hard, tough, corrosion resistant
Cutlery, sinks Easy to clean, no surface finishing required, recyclable Difficult to join in school workshop, special welding equipment needed |
|
|
Everything about carbon steel...
|
Ductile
Nail, screws, nuts Recyclable Will rust if unprotected |
|
|
What are non-ferrous materials...
|
Don't contain iron, are not magnetic, good conductors of heat and electricity
|
|
|
Everything about aluminium...
|
Lightweight, soft, ductile, malleable, corrosion resistant
Kitchen foil, drink cans Recyclable, easily cast Expensive, difficult to weld |
|
|
Everything about copper...
|
Malleable, ductile, good heat and electrical conductor, Corrosion resistant
Electrical cables, pipes Recyclable, easily soldered Expensive, will tarnish |
|
|
Everything about zinc...
|
Corrosion resistant
Negative battery terminals, used for galvanising Recyclable Brittle |
|
|
Everything about brass...
|
Alloy of copper and zinc
Corrosion resistant, good fluidity, conductor of heat and electricity Plumbing fittings High lustre finish, tough, recyclable, casts well Expensive |
|
|
Ductility
|
Ability to be drawn into smaller, thinner sections
Copper Electrical wires |
|
|
Malleability
|
The ability to be deformed by compression without tearing
Mild steel Car body panels |
|
|
Hardness
|
The ability to withstand abrasive wear and indentation
Stainless steel Sinks |
|
|
Toughness
|
The ability to withstand sudden shock loading without
fracture Mild steel Nails |
|
|
Elasticity
|
The ability to return to original shape once deforming force is removed
High carbon steel Springs |
|
|
Tensile strength
|
The ability to withstand being pulled apart
Carbon steel Nails |
|
|
Compressive strength
|
The ability to withstand being squashed
Mild steel Car body panels |
|
|
Shear strength
|
The ability to withstand being slid apart
Stainless steel Security shear nuts |
|
|
Plasticity
|
The ability to change shape without breaking
Acrylic Garden chairs |
|
|
Durability
|
The ability to withstand weathering
All plastics Garden furniture |
|
|
Polymers
|
Made from molecules formed into long chains
Waterproof |
|
|
Thermoplastics
|
Thermoplastics can be heated reshaped and cooled to set many times
Made form long chains of molecules with few cross links Have plastic 'memory' - when reheated return to original shape unless damaged by overheating |
|
|
Everything about acrylic...
|
Good impact strength, lightweight, electrical insulator, durable
Fish tanks Recyclable, environmental stability, colours Scratches, soft, bad chemical resistance |
|
|
Polyethene
|
Tough, chemical resistance, soft, flexible, electrical insulator
Carrier bags, buckets Recyclable- but most ends in landfill sites |
|
|
PVC
|
Chemical resistance, lightweight, electrical insulator,
tough, durable Pipes, bottles Recyclable, cheap Dangerous fumes when burnt |
|
|
HIPS
|
Tough, high impact strength, electrical insulator
Toys, cutlery Colours, recyclable Expensive, non-biodegradable |
|
|
ABS
|
High impact strength, tough, durable, chemical resistant, electrical insulator, lightweight
Toys Colours Expensive |
|
|
Thermosetting plastics
|
Long chains of molecules that are cross linked = rigid molecular structure.
Soften when heated so can be shaped, but only once. Electrical insulators, hard, waterproof |
|
|
Everything about polyester resin...
|
Electrical insulator, hard, brittle, heat and chemical resistance
Casting, adhesives Colours, water resistance Contracts on curing, excess heat |
|
|
Everything about urea formaldehyde...
|
Stiff, hard, brittle, high tensile strength, scratch and stain resistant
Buttons, electrical castings Coloured, high surface hardness Toxic fumes when it cures |
|
|
Carbon fibre
|
Made of very thin fibres and carbon atoms
Skis, racket frames High strength to weight ratio, high tensile strength Expensive, weak when compressed |
|
|
Glass reinforced plastic
|
Plastic reinforced with glass fibres and epoxy resin matrix
Boats hulls, canoes Lightweight, good strength to weight ratio, durable Time consuming to make, cutting = dangerous to breath dust |
|
|
Shape memory alloys
|
They remember cold form shape when heated
Glasses - nitinol Anti-sclading valves Orthodontic wires - good elasticity, tensile strength, lightweight, expensive |
|
|
Photochromic paint
|
Changes colour when exposed to UV or sunlight - reversible
Used in textiles, vans Ability will decay over time |
|
|
Reactive glass
|
Because of added silver halide micro crystals in glasses
Smart glass in windows when voltage is applied Expensive to manufacture and install |
|
|
Carbon nanotubes
|
Cylindrical structure
Lighter but stronger than steel, flexible, conducts heat and electricity, inert, gives a hard tough finish to paint, high tensile strength, expensive, toxic |
|
|
Marking out
|
Take measurements from a datum - prevents cumulative errors
Timber from face side and edge |
|
|
Steel rule
|
For measuring up to 300mm in length
Rigid Ends can wear out |
|
|
Measuring tape
|
For making longer measurements
Can twist and break |
|
Try square
|
Marking out right angles on wood or plastic
|
|
|
Engineer's square
|
marking out right angles on metal or plastic
|
|
|
Mitre square
|
Marking out angles of 45 or 135 degrees
|
|
|
Marking gauge
|
Marking lines parallel to the face edge and side on wood
Set using steel rule. Consists of stock that slides up and down stem. Spur is pushed into wood |
|
|
Cutting gauge
|
Used for cutting across the grain
Blade instead of spur |
|
|
Mortise gauge
|
Marking two parallel lines fro a mortise and tenon joint
Two spurs |
|
|
Scriber
|
Scratch the surface of metal or plastic lightly
On metal use engineer's blue |
|
|
Centre punch
|
Used to make an indent for drilling in metals
|
|
|
Dot punch
|
marking the centres fro dividers
|
|
|
Templates
|
Used when a number of identical shapes need to be marked out
|
|
Micrometers
|
Used to take accurate measurements
|
|
|
Saws
|
Cut material not needed away from material that is
Teeth set in alternate directions to make a kerf. Must be wider than blade so saw doesn't get stuck. Cut to the waste side for finishing room |
|
Coping saw
|
Cuts curves in wood and plastic
Blade can be removed from frame and rotated but can break easily. Difficult to control on straight lines |
|
Tenon saw
|
General purpose woodworking saw
Depth of cut limited to blade length |
|
|
Dovetail saw
|
For small accurate work
Shorter than tenon saw Fine cut because of smaller teeth Not robust for general work |
|
Adjustable hacksaw
|
Used for fine or rough work in plastic and metal
Replaceable blade, can snap easily |
|
Jack plane
|
Smooths and flattens wood to size
Heavy and jams easily |
|
Smoothing plane
|
FInishing a surface and for on end grain
jams easily |
|
Block plane
|
Removes sharp edges
Can be used in one hand Jams easily and not good on large surfaces |
|
Gouge
|
Curved blade for carving
|
|
|
Firmer chisel
|
General purpose cutting or carving in wood
|
|
|
Bevel-edged chisel
|
used for cutting dovetails
|
|
|
Mortise chisel
|
Deeper balde for cutting mortise joints
|
|
|
Cold chisels
|
used to cut sheet metal by shearing across or chopping down
One end hardened and tempered other soft to absorb shock |
|
|
Rasp
|
Quick removal of waste wood
Clogs easily |
|
Surform
|
Fast removal of soft material
Blades break easily |
|
|
Cross filing
|
Removes waste rapidly
|
|
|
Draw filing
|
Removes marks left in wood from cross filing
|
|
|
Files
|
Made from high carbon steel, body is hardened and tempered tang is soft and fits in handle.
|
|
|
Flat file
|
Removes waste on large flat surfaces
Has a safe edge to prevent cutting into edge when filing a corner Brittle of dropped |
|
|
Round file
|
Creates curves and fillets
Small cross section = weak |
|
|
Three square file
|
Cuts into corners between 60 - 90 degrees
|
|
|
Twist drill
|
Used to create holes in materials
twist carries waste away in swarf Breakable |
|
|
Flat bit
|
Used to drill a hole all the way through
Will split underside of wood if not supported |
|
|
Countersink bit
|
Creates depression for head of countersunk screw
Chatters at high speeds |
|
|
Hole saw
|
Used on thin materials to create large drills
Burns at too high speed |
|
|
One-off
|
Highly skilled workers, constant discussion with clients, specialist area of work, unique products, made to measure, expensive, time consuming
|
|
|
Batch
|
production line set-up, workers semi skilled and flexible, quick response to customer demands, production line can be changed quickly , tools have to be reset for new production run
|
|
|
Mass
|
Semi-automated, much computer control, investment in machinery, low unit costs, 24/7, initial costs are high
|
