SCREW ONLINE NOTES AND MECHANIC DIESEL

 Screw:-

i)- Screw is used to joint or assemble two parts. 

ii)- Entire body contains thread except head.

iii)- Nut is not required where screw is used. 

iv)- screw are like bolt.

v)- Screw used in wooden work is called wood screw.

vi)- Screw used in metal and non-metal are called machine screw.

machine screw:-

i)- When nut cannot used in assembly in that situation machine screw are used

ii)- The component of assembly directly tighten with screw for this thread in component is must.

iii)-  Machine screws are used for general assembly work.

iv)-  It is manufactured in both COARSE and FINE series.

Types of machine screw:-

i) There are different types of machine screw used in machine work.

1- Hexagonal Head Screw. 2- Hexagonal Socket Head Cap Screw. 3- Square head Counter

Sink Head Screw. 4)- Square Head Screw.

1- Hexagonal Head Screw:-

i)-This type of screw is used,when there is no disturbance in the assembly of component.

ii)- The head may out from the job surface and machine will work smoothly.

iii)- This type of screw is made Brass and Steel.

iv)- Simple work Steel screw is used and Electrical work Brass screw are used. 

Hexagonal Head Screw

2- Hexagonal Socket Head Cap Screw:-

i)- These type of screws are used where need to stop.

ii)- It is used for obstacle on the surface of assembly of component then the screw are used after counter boring.

iii)- This type of screw is made Brass and Steel

iv)- Indian Standard these are used in 1.6 mm to 36 mm.

Hexagonal Socket Head Cap Screw

3- Square head Counter Sink Head Screw:-

i)- Counter sink head screw  are accurately assembled in threaded components after assembling.

ii)- It is not growing the upper surface of the machine after assembling.

iii)-These screw classified according to different type of counter sink head screw.

Square head Counter Sink Head Screw

iv)- There are four types of counter sink head screw are used.

a)- Slotted counter sink head screw. ( M 1 to M 20)

b)-Cross recessed counter sink head screw. (M 1.6 to M 10)

c)- Slotted raised counter sink head screw. (M 1 to M 20)

d)- Cross recessed raised counter sink head screw. (M 1.6 to M 10)

4)- Square Head Screw:-

i) When assembly remove and tight in short time again and again this types of screw are used.

ii)- Wrench is used to tight and open these screw washer is attached bellow the head.

iii)- Aim of the washer to keep clean surface of the work piece.

iv)- Another machine screw which is used for light work

a)- Pan head machine screw. b)- Cheese head machine screw.

c)- Raised Cheese Head Machine Screw.  d)- Round head screw.

Square head screw

Set screw:-

i)- Hexagonal shocked set screw has no head and do not obstruct on surface assembly of the work piece.

ii)- According to the work set screw are available in different point.

iii)- The point of these screw are fasted in the metal or tighten without any damage of work-piece.

iv)- These set screws are mostly used in fastening with shaft of pulley & collar.

v)- They are used there where space is limited or shortage of space.

Set screw

Grub Screw:-

i)- Grub screw is used equal to hexagonal head screw.

ii)- But these are used in light work.

iii)- According to work grub screw available with different point.

iv)- Grub csrew classified by according to shape of the point.

Gurb screw

Thumb Screw:-

i)- These type of screw which is open and tight with the help of pressure thumb.

ii)- This screw requirement of assemble and disassemble of the component frequently.

iii)- It is made by Brass or Non ferrous metal, 

iv)- According to specification of thumb screw are Five types.

a)- Thumb screw partially thread. 

b)-  Thumb screw (fully) thread.

c)- Slotted Thumb screw partially threaded.

d)- Slotted Thumb screw fully threaded.

e)- Flat thumb screw.

v)- Size are specification by thumb screw is M 1.6, M 2, M 1.5, M 4, M 5, M 6, M 8, and M 10.

vi)- Example:- AM 6 X 12: IS :3726 - 4.6 ( A= Type, M 6 = size, 12 mm = Nominal length, 4.6 = Property class is designated).

Thumb screw

Self Taping Screw:-

i)- Self taping screw is used where very thin section metal sheet is used in assembling.

ii)- These screw cut thread itself by its use.

iii)- There joint are anti vibrated.

iv)- They are assemble and disassembled many time.

v)- There are Three types a)- Thread Farming, b)- Thread Cutting, c)- Self-persing and Self Taping screw.

a)- Thread Farming:- 

i)- This type of metal screw makes matching thread after the removal of metal.

ii)- These are useful for malleable, soft and thin metal.

Thread Farming

b)- Thread Cutting Screw:- 

i)- This type of cut matching thread in a hole as thread cutting tap in screw and action for thread shape outside raise.

ii)- It is most useful for hard or brittle metal are self taping.

Thread Cutting Screw

c)- Self persing and Self Taping screw:-

i)- In this screw connection persing and two mouth thread.

ii)- This screw is used by special gun.

iii)- Self Taping screw are available in different size a)- Cross Recessed, b)- Slotted head screw.

iv)- According to Indian Standard(I.S) these contains two points AB type and B type.

AB type- Self pressing and B type- Thread forming type.

Designation of self taping Screw:- The name of self taping screw is designated according to Type, screw size no, Length, and Indian standard.