Characteristics and Properties Of Timbers Flashcards
What is a knot in a piece of wood!?
A knot in a timber marks where a branch once grew out on the tree.
Why are timbers containing knots less likely to be used!?
Knots often fall out from planks as they shrink, leaving a hole.
What are timbers with knots in used for!?
Decoration purposes
How can the colour of a timber be altered!?
The colour of planks can be altered using wax, varnishes, stains and paints
Do hardwoods and softwoods both produce growth rings!?
Yes- they are close together for hardwoods and further apart for softwoods.
What are the two types of blood vessels that run through hardwood!?
fibres and pores
What is a working property!?
They are used to describe the properties of materials such as hardness, toughness and durability.
What is elasticity!?
The ability of a material to stretch and return to its original shape
Do timbers contain elasticity properties!?
Timbers are generally not very elastic, although some are a little more than others
EG yew for bow and arrows
What is tensile strength!?
The ability of a material to withstand being pulled by a certain amount of force
Do timbers have a high tensile strength!?
Yes- Timbers have higher tensile strength than compressive strength.
What is compressive strength!?
The ability of a material to withstand being crushed by a certain amount of force
Do timbers have high compressive strength!?
The denser the timber, the greater the compressive strength,
Give an example of compressive strength…
oak has a higher compressive strength than balsa
