Category #1
Name five sheet metal hand tools used in the workshop.
Circumference Rule
Scribe
Centre Punch
Dividers
Cross Pein Hammer
Stretching Hammer
Combination Square
14" right hand snips
11" left hand snips
Trammel Points
Name three types of projection.
Oblique
Isometric
Third Angle
The process of softening a metal is called....
Annealing
Provide three safety precautions when using a drilling machine.
Be familiar with stop/start function
Drill correctly and firmly in position
Workpiece is firmly and properly clamped
Workspace free from clutter
Wear PPE - goggles, footwear, clothing
How does carbon content affect steel?
It increases the tensile strength, toughness and hardness of the steel as it increases
Reduces ductility
Name three good conductors.
Copper
iron
Silver
Brass
Lead
Stainless Steel
Aluminium
Give two pieces of information about non-ferrous metals.
Do not contain iron
High resistance to corrosion
What would you use to remove excess weld metal before painting?
Electric Angle Grinder
Name three bench stakes used in sheet metalwork.
Hatchet Stake
Bick Iron
Creasing Iron
Funnel Stake
Mandrel Bar
Name three ways that you can stiffen sheet metal.
Form angles, hems/edges or flanges along the edge
Rolling/curving the metal
Cross checking of sheets or panels
Swaging
Dishing
Use applied stiffeners e.g. flat bar, etc.
Name three things that you can do to prevent rust.
Hot dip galvanising
Coating
Painting
Electro-plating
Give three advantages of using pop rivets in sheet metalwork.
Lighter in weight than solid rivets
Designed for blind or one-sided riveting for areas that are usually inaccessible
Only one operator required
Fast to install
What is the allowance for a wired edge?
2.5 times the diameter of the wire
What does RSA and RSC stand for?
RSA = Rolled Steel Angle
RSC = Rolled Steel Channel
Why is it necessary to pre-form or pre-shape a sheet or plate before rolling?
Prevents flats forming at joints
What is a toe board and what is it used for?
Prevent tools, materials or equipment falling off the edge of a working platform like a scaffold
Name three steel sections used in sheet metal work and where they can be used.
Flat Bar - stiffening edges where metal is too thick to be edged or hemmed
Angle Iron - extra stiffening, duct flanges, frames, brackets/supports
Channel Section - support frames for air handling units, duct supports/brackets
Round Bar/Rod - used for stiffening the edges of sheet metal work
Box Section - used mainly for framework in cabinets, tables, etc.
Ductility is....
the ability of the metal to be stretched without breaking
List three advantages of a wired edge.
Adds strength
Adds to appearance
Eliminates sharp edges
Safer to handle
List three advantages of swaging a circular duct.
Strengthens component
Acts as a stop pipe/slip joint
Appearance
What % of carbon does Medium Carbon Steel have?
0.5% - 0.7%
Find the length of a rectangular tank with a capacity of 945 litres, the height is 900mm and the width is 700mm. 1000cc = 1 litre.
Volume = L x W x H
L = Volume divided by W x H
Answer: 150cm or 1500mm
Name two other types of sheet metal edges (not wired edge) and give the allowance for each.
Single Hem or Safe Edge, allowance is width of hem, width = 6, 8, 10, 12mm
Double Hem or Double Edge & Flatten, allowance 2 width - 1.5mm, w = 10, 12mm
Calculate the length of wire needed to finish the tops of 70 cylindrical tanks of 600mm diameter.
Amount of tanks x 3.14 x D
70 x 3.14 x 0.6 = 131.88mm
What are Class B fire extinguishers used on?
Flammable liquids like petrol or oil