JOINING METALS

Question 1

two types of joining metal

Answer 1

permanent and non-permanent

Question 2

what is permanent joining

Answer 2

includes welding and brazing

Question 3

what is no-permanent joining

Answer 3

includes screws nuts and bolts

Question 4

brazing

Answer 4

sometimes called hard soldering

uses brazing rods which melt at 800 degrees

uses brass filler metal which bonds to steel

uses a gas torch

Question 5

welding

Answer 5

strongest way to join metals like steel.

the pieces are heated and melted and fused together to form one piece

Question 6

oxy-acetylene

Answer 6

uses two gases oxygen and acetylene that burn with a very high temperature of 2000 degrees to melt a mild steel welding rod

Question 7

what are the types of welding

Answer 7

oxy-acetylene or gas-welding

arc welding

MIG welding

spot welding

Question 8

ARC and MIG welding

Answer 8

uses a dc current to form a high temperature electric arc this melts the steel filler rod

Question 8

what does MIG stand for

Answer 8

Metal Inert Gas

Question 8

what are the advantages of MIG

Answer 8

easier to learn than gas

lower heat therefore less distortion of metal

Question 9

what are the disadvantages of MIG

Answer 9

needs electrical contact so metal has to be clean

Question 10

describe ARC welding

Answer 10

uses a short steel rod coated in flux as the rod touches the work piece an electric arc is formed the flux coats the weld keeping out oxygen

Question 11

disadvantages of arc welding

Answer 11

produces UV light which can cause severe eye damage

Question 12

spring washers

Answer 12

these are made from high carbon steel and are placed onto a bolt underneath a nut. they grip the nut to prevent it being shaken loose

Question 13

nylock nut

Answer 13

have nylon plastic insert

when the bolt is tightened it forms it’s own thread in the nylon which grips the bolt, preventing it from working loose

Question 14

countersinking

Answer 14

by cutting a countersink into a fixing hole and using a countersunk screw you can achieve a flush fixing

Question 15

pop riveting

Answer 15

used to join thin pieces of sheet metal ( can be used on wood and acrylic)

useful if you only have access to one side of the material

can be undone by drilling through

Question 16

thread cutting

Answer 16

instead of using nuts and bolts it is possible to cut threads in mild steel and non ferrous metals using taps and dies

Question 17

soft soldering

Answer 17

is a relatively weak joint

uses a low melting point metal (solder ) to the work pieces to form a bond between them, without melting the work pieces

solder is very soft so the joint is relatively weak