Joining Metals Flashcards
What is Gas Welding?
Using a acetylene torch to heat up the joint
Mixture of acetylene gas and oxygen produces small hot flame melting filler rod and surrounding metal
What is Metal Inert Gas Welding (MIG)?
Often used in schools to weld steels
Electric spark creates heat by arcing between electrode and work-piece
Electrode melts and fed in from roll of steel wire
Area cooled with gas mixture of Argon and Carbon Dioxide
What is Tungsten Inert Gas (TIG)?
Used to weld non-ferrous metals
Same as MIG welding but electrode doesn’t melt
What is Spot Welding?
Form of resistance welding
Used for melting thin sheet steel together
Electrodes sandwich metal together and current is passed between them
Resistance creates heat to bond the two metals in a tiny spot
What must you always wear when Welding?
Visor/Protective Facemask to protect Eyes
and Gloves to protect hands
What is Soft Soldering?
Join metal parts together using lead-free alloy
Used for light applications eg. electrical connections and plumbing joints
What is the process of Soft Soldering?
1) Flux is applied to join to clean it
2) Fluxed joint is heated using gas torch or metal soldering bit
What is Hard Soldering/Brazing?
Used for heavier applications as joint is stronger
Brass Bonding Alloy (Spelter) melts at much higher temperature
Used for joining Mild Steel and sometimes Copper
What is the process of Hard Soldering/Brazing?
1) Borax Flux is mixed to a paste with water and applied to the join to clean it
2) Heated to orange colour with gas torch and spelter melts around the join
What are the different heads of Bolts?
Countersunk
Cheese Head
Hexagonal Head
Socket Head
What do Mechanical Joints do?
Allow different materials to be joined to metals
Can be dismantled for repair/maintenance
What are sometimes used instead of a nut?
Threads - sometimes cut into one of metal pieces, available in many different lengths
What is a Countersunk head and Cheese Head tightened with?
Screwdriver
What is a Hexagonal Head tightened with?
Spanner
What is a Socket Head tightened with?
Allen Key
How are Wing Nuts tightened?
Hand
What is Spring Washer used for?
Stop Nut vibrating loose
What is a Washer used for?
Spread pressure
Protect surface of metals being joined together
What are used for Mechanical Joints?
Nuts and Bolts (with washers between)
What are Rivets?
Used to make more permanent joint that Nuts and Bolts
Hold material together by forming a head on both sides of material
What are Rivets usually made from?
Soft Mild Steel, Copper or Aluminium
What are Pop Rivets?
Two parts: pin and rivet
Pop rivet passed through materials
Rivet pliers pushed on top of rivet and handles pulled together making the pin break off and leave rivet permanently fixed
