stock forms

Question 1

what are the categories of metals

Answer 1

ferrous
non ferrous
alloys

Question 2

what is low carbon steel

Answer 2

malleable, ductile good tensile strength.

Question 3

medium carbon steel

Answer 3

these carbons are less ductile, hard, malleable and good tensile strength

Question 4

grey cast iron

Answer 4

distributes heat evenly and withstands compression and deformation

Question 5

white cast iron

Answer 5

excellent resistance to abrasion, hard and brittle and good tensile strength

Question 6

what are the 6 non ferrous metals

Answer 6

-aluminium
-copper
-silver
-gold
-titanium
-tin

Question 7

list four non ferrous alloys

Answer 7

-bronze
-brass
-duralumin
-pewter

Question 8

what are the three categories of timber

Answer 8

hardwoods/softwoods and manufactured boards

Question 9

what range are natural timbers stock forms

Answer 9

-rough sawn
-planed square edge (PSE)
-planed all round (PAR)

Question 10

what is rough saw timber

Answer 10

-the cheapest stock from
-surfaces are rough from industrial saws
-cheap due to little processing

Question 11

what is planed timber

Answer 11

-desired to have 90 degrees edge on one or more sides

Question 12

how much timber is removed from PSE and PAR

Answer 12

around 3mm from original cut

Question 13

what is the difference between PSE and PAR

Answer 13

PSE has one square edge
PAR is square on all sides (more expensive)

Question 14

what are mouldings

Answer 14

machined profiles made for functional and aesthetic purposes

Question 15

what are manufactured boards

Answer 15

boards that have been man made for example chip board or MDF

Question 16

what are advantages of manufactured boards

Answer 16

-cheaper than natural timbers
-can be cut to larger scales
-can be enhanced with special properties such as water resistance or fire resistance
-can be aesthetically enhanced

Question 17

name 6 soft woods

Answer 17

-pine
-Douglas fir
-Cedar
-Spruce
-Redwood
-Larch

Question 18

what are characteristics of softwoods

Answer 18

fast growth
low cost
straight shape
lightweight
easily farmable

Question 19

name six hard woods

Answer 19

-Oak
-Ash
-Teak
-Beech
-Birch
-Mahogany

Question 20

what are characteristics of hard wood

Answer 20

slow growing
need more land
expensive
best aesthetic qualities
stronger more durable

Question 21

how is MDF made

Answer 21

form fine wood dust particles bonded with resin under pressure, where chipboard uses larger chips

Question 22

qualities of MDF

Answer 22

perfectly smooth finish
uniform density
ideal for CNC milling

Question 23

what are the main performance characteristics of wood

Answer 23

-grain pattern
-warpage, shrinkage or splitting
-machining qualities
-resistance to decay and moisture
-toxicity

Question 24

what causes warpage

Answer 24

caused by different moisture levels in different parts of the wood

Question 25

what is shrinkage

Answer 25

as wood dry its volume decreases

Question 26

what is splitting

Answer 26

as wood dries the fibres separate, usually when wood dries too quickly

Question 27

what is wood when it is anistrpoic

Answer 27

when the grain gives natural wood different physical properties in different directions --it is an anisotropic material

Question 28

what woods arent anisotropic

Answer 28

manufactured woods

Question 29

what are types of surface defects in woods

Answer 29

-knots -machining marks -insects, disease or rot

Question 30

what is seasoning

Answer 30

it is when the wood is dried to prevent warpage, shrinking and splitting

Question 31

what are the two different types of seasoning

Answer 31

-air dried -kiln dried

Question 32

what are the three types of wood distortion

Answer 32

-diamond shrinkage -cup shaped -uniform shrinkage

Question 33

what causes shrinkage

Answer 33

moisture levels

Question 34

what are the advantages of seasoning

Answer 34

-makes the wood more stable -less likely to decay or rot -less likely to corrode metals -absorbs preservatives more easily

Question 35

what types of testing can be used for woods

Answer 35

-strength (tensile) -toughness -hardness -density -corrosion -malleability -elasticity