HACKSAW FRAME - BLADE - ITI-FITTER ONLINE NOTE

What is Hacksaw:-

i)- It is also cutting tool and also called iron saw.

ii)- It is used to cut pipe,sheet and different types of metal.

iii)- The processing of cutting by hacksaw is called hack sawing.

iv)- It has two parts 1)- Frame and 2)- Blade.

1)- HACKSAW FRAME:- 

i)- Hacksaw frame has right angle bent both side.

ii)- The handle is fitted to its one side end and second side tension sliding screw is fitted.

iii)- A hacksaw frame is used along with a blade to cut metals of different sections. 

iv)- It is specified by the type and maximum length of the blade that can be fixed. 

v)- For Example - Adjustable hacksaw frame - tubular - 250 - 300 mm or 8" - 12

vi)- Hacksaw frame are two types a)- Solid Frame and b)- Adjustable Frame.

a)- Solid Frame:- 

i)- It is made of iron sheet which is bent at right angle from both side.

ii)-A blade of a particular standard length can be fitted to this frame.300 mm or 250 mm.  

b)- Adjustable Frame:-

i)- It is divided into two parts so that its length can be increased or decreased by the help of pin fitted with the frame.

ii)- This frame helps to different types of blade can be fitted.

iii)- It is mostly made of sheet or pipe.

iv)- Its handle is made of wood,Aluminium or light metal.

v)- Its handle are three types a)- Straight type, b)- Adjustable pipe type, c)- Pistol-Grip type.

vi)- Parts of a hacksaw frame 1)- Handle, 2)- Frame, 3)- Tubular frame with holes for length adjustment, 4)- Retaining pins, 5)- Fixed blade-holder, 6)- Adjustable blade-holder, 7)- Wing-nut.

2)- HACKSAW BLADE:-

i)- Hacksaw blade generally made of High Carbon Steel(H.C.S), High Speed Steel(H.S.S) and Tungsten Steel. all are hard and temper.

ii)- Specification:- Hacksaw blades are specified by the length, pitch and type of material. (The width and thickness of blade is standardized) Example 300 x 1.8 mm pitch LA all-hard blade.

iii)- Blade length- 250 mm to 300 mm, Blade Breadth- 13 mm to 16 mm, Blade Width- 0.63 mm to 0.80 mm. and Teeth of Pitch- 0.8 to 1.8 mm are available in market.

iv)- Some blades have teeth both side.

v)- There is hole on both sides of blade and its size depends upon distance between two hole.

vi)- Parts of a hacksaw blade  1)- Back edge, 2)- Side, 3)- Center line, 4)- Pin holes.

vii)- There are two types of blade a)- All hard blade, b)- Flexible blade.

viii)- There are two types of saw teeth a)- Staggered Saw,  b)- Wave Saw.

ix)- Selection of blade:- The selection of the blade depends on the shape and hardness of the material to be cut. 

Pitch selection:-

i)- For soft materials such as bronze, brass, soft steel, cast iron, heavy angles etc. use a 1.8 mm pitch blade use.

ii)- For tool steel, high carbon, high speed steel etc. use a 1.4 mm pitch.

iii)- For angle iron, brass tubing, copper, iron pipe etc. use a 1 mm pitch blade.

iv)- For conduit and other thin tubing, sheet metal work etc. use a 0.8 mm pitch.