FITTING Workshop :- 2) Fittery Hand Tools

In engineering, generally in light & medium section some common hand tools are used for particular Work. They have very special features. Punch, Try square, Hammer, Vice Screw driver, spanner, Adjustable wrench are the common hand tools used in workshop.

(1) PUNCH: A punch is a most common marking hand tool which is used for marking out work locating centers etc. After marking out on work piece, it must not be swept away. For this purpose all useful marked lines are to be punched by means of punch. It is known as punching operation. At the time of punching obey the following points.

1. Punching (Dot) should be at equidistance and at sufficient space.

2. It should be at light (Normal ) depth & perfect only on the marked line.

TYPES:

1. Dot punch: It has a grinding angle of 60°, used for punching operation on marked line.

2. Center punch: It has a grinding angle of 90°, used for punching before drilling. So that the drill can’t be escaped but insert properly.

3. Prick punch : Having the grinding angle of 30°, used for punching on soft metal like Cu AI, etc.

(2) TRY SQUARE:- Try square is known as a checking tool. It is made in one piece of two different parts 1. Base 2. Blade. It is used when it is necessary to get another edge or surface exactly at a right angle (90°) to an already truly made edge or surface & also used for laying out work. There are mainly two types of try square.

1. Fixed 2. Adjustable

Generally, fixed try square is used in workshop for checking right angle of jobs.

(3)HAMMER: Hammers are used to strike on a job or on a tool. They are made of forged steel of various sizes (Weight) & Shapes to suit various purposes. A Suitable range would be from 0 11 to 033 kg. For light work such as riveting & dot punching, 0.45 kg. For chiseling, 0.91 kg. For heavier work such as chipping.

A hammer consists of four paris namely peen, head, eye & face. The eye is normally made elliptical in shape, accommodates handle or shaft. The face is hardened & polished well, slightly convex, instead of flat to avoid spoilage of the surface to be hammered.

Hammers are classified according to the shape of peen as follows:

1.Ball peen

2. Cross peen

3 Straight peen

4. Claw

5. Mallet etc

(4) VICE:- The vice is the most common tool for holding work firmly. Various types of vices are used for multiple purposes. They include Bench vice, Pipe vice, Pin vice, Leg vice, Machine vice, Revolving vice, Carpentry vice etc.

(1) BENCH VICE It must be firmly fixed to the bench with nuts & bolts. This vice consists of C. I Body (a fixed jaw), a movable jaw both of cast steel, a handle, a square threaded screw (spindle) & a nut. Separate jaw plates are fixed to the jaw by means of set screws. The size of a vice is known by the width of its jaws.

(2)PIPE VICE The pipe vice is used for holding tightly the round section of metal, tubes, pipes, etc. In this vice, the screw is vertical so the movable jaw moves vertically. They grip the work at four Points on its “V”cut surfaces.

(5) SCREW DRIVER:- A screw driver consists of a wooden or plastic handle & a steel blade having various shapes. It is of various length & thickness, to suit the corresponding size of the slots, on the screw heads. It is generally used for fixing or opening the screw, stud or bolt which are having the slot on their top of head.

Following are the main types of screw driver.

1. Ordinary

2. Philips (for way)

3. Ratchet

4.Off set

(6) SPANNERS: Nuts, bolts, screws etc. are used for fasting various machine parts with each other.

The tools which are used to open & fix them are known as spanners. Generally, they are made of vanadium steel by means of drop forging process on them.

TYPES: Following are the main types.

1.Fixed

2. Ring type

3. Box type

4. Allen key spanner

5. Adjustable wrench

6. pipe wrench

(1)FIXED SPANNER:- It is divided as single ended and double ended spanner. It is most commonly used in any engineering units. Also it is available in both meaning system metric as well as British. The width between its jaws are generally 1.5 D+3mm in metric system. Where D-diameter for bolt or nuts. (2)RING SPANNER- It is the spanner which can be holed all six faces of bolt’s head or nut equally, because of its spring type shape. So that it can be gripped very tightly. Also it is used at complicated space due its proper design.

(3)ADJUSTABLE WRENCH:- It can be expanded by means of its jaws up to its particular range of length. It can works instead of many spanners of nearer sizes