Unit - 3

Fitting Operations & Power Tools

Q1) Describe the term Fitting work.

A1) Fitting work is a very important work in engineering point in fitting shop unwanted material is removed with help of hand tools. It is done for manufacturing and repair purposes. Commonly used tools are hacksaw, files chiesel etc.

Q2) Define Vices and its type?

A2) Vices:

Vices are the most suitable and widely used tools for gripping different jobs in position during the various operations carried out in a fitting shop.

Common types of Vices

Bench Vice: It is a common tool used for holding jobs. It consists of cast iron body and cast-iron jaws. 10 is fixed to the body and second slides on a square thread screw with the help of a handle. The jaws are opened up to required length job is placed in the two jaws and fully tightened with handle.

Hand Vice: Hand vice is used to grip very small objects. These are made in different shapes and sizes. It consists of two Steel legs hinged together at the bottom and carrying the hardened Steel jaws at the other end point a spring attachment is is provided between the two legs, which always tend to keep the jaws separate. A screw is fast and to one leg and passes through the other point at the free end of screw, a wing nut is provided. The peace to be held is gripped between the serrated jaws by tightening the wing nut.

Pin Vice: A pin vice is used for holding very small pieces like wire nails and pins etc. It is nothing but a small form of collect chuck. It consists of a handle and a tapered nose carrying a small collect chuck at its end.

Pipe Vice: It is used to hold pipes. It consists of a vertical screw with square threads. Handle is attached on the top of the screw. Immovable Jo is fixed on the lower end of the screw. It grips the pipe at four points.

Q3) What is the work of Fitting Tools?

A3) Fitting shop tools are classified as under:

(a)  Clamping tools

(b) Measuring and marking tools

(c)  Cutting tools

(d) Striking tools

(e) Drilling tools

(f)    Threading tools

Q4) Explain in brief the use of Cutting tools?

A4) The tools which are used to remove the material are known as cutting tools. These tools are:

a) Hacksaw: Hacksaw is used for cutting of rods, flats etc. The Blade of hacksaw is made up of high carbon steel. Frame is made from mild steel. The length of blades varies from 8 inches to 14 inches but generally 12-inch blade is used in fixed frame hacksaw. The thickness and width of blade are 1 mm and half inch respectively. Blades are classified as under:

(i)Depending upon the direction of cut

(a) Forward cut

(b) Backward cut

(ii) Depending on the picture of the teeth

(a) Coarse (8-14 teeth per inch)

(b) Medium (16-20 teeth per inch)

© Fine (24-32 teeth per inch)

Q5) What are the types of hacksaw frames?

A5) Types of hacksaw frames

In fixed frame only one type of blade is used whereas in adjusted frame the length of the frame can be increased or decreased as per requirement.

Pitch of hacksaw

It is the number of teeth on blade in one centimeter. Hacksaw blade with small page is used for thin sections and large Pizza used for thick sections.

Q6) Define the term file.

A6) File is also a mouth tooth tool. it is used to remove the material by rubbing it on the metal. Classification of files on the basis of grade

Rough (20 teeth per inch)

Second cut (40 teeth per inch)

Smooth file (50-60 teeth per inch)

Dead smooth (hundred teeth per inch)

Classification on the basis of shape and size

1. The length of files vary from 4 inch to 14 inch.

2. The shapes available are flat, square, round, triangular, half round etc.

Q7) Define the Classification on the basis of number of cuts?

A7) i) Single cut

The teeth are cut in parallel rows at an angle 60 degree to the face.

ii)Double cut

In addition, two single cut, and other row of teeth is added in opposite direction.

Chisels: These are used for keeping away the material from the workplace. These are made up of high carbon steel generally 5 inch to 8 inch long. The top is flattened and a shop cutting edge is made on the bottom side.

Chisels are classified on their shape and weight of the cutting edge. Commonly used forms of chisels are flat, crosscut, half round and diamond point chisel. Cutting angle of chisels is kept as under

(a)  For hard material (70 degree – 75 degree)

(b) For medium hard material (60 degree)

(c)  Four soft material (90 degree)

Q8) Write a short note on Striking tool?

A8) Farmers are the only tools generally used for striking in fitting shop. These are used for sleeping, fitting, punching etc. Hammer consists of a heavy iron body with wooden handle. The weight ranges from 0.25 kg to 2kg.

Types of hammers: Ball Peen. Straight, Peen and cross peen hammer.

Q9) What is the function of Portable Power tools?

A9) The source of energy is battery, electricity or compressed air. Example, portable drill machine, portable grinder, portable metal cutting machines.

Q10) Explain in brief the function of Fitting process

A10) Fitting process

a) Marking

b) Scrapping

c) Chipping

d) Grinding

e) Drilling

f) Measuring

g) Reaming