What is Bench vice. What are the parts Bench vice.

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Bench vice is a holding tool. It is the most used or most popular type of holding tool. the specimen on which job work is to be performed is fixed secured tightly in the bench vice and then mechanical work can be performed on a bench vice. bench vice is a non portable tool as the name suggests, this voice is mounted on a bench.

Parts of bench vice

There are five main parts of a bench vice described below


Body is an outer part and main body of vice. body contains base of bench vice this base is attached with the bench to establish a strong mounting with Bolt and nuts.


Slider is the part which will move to and fro directions. the slider will help mounting or Demounting of the specimen for job work in the bench vice.


Screws is connected with the slider.  with the help of the screw, slider will be capable to move forward and backward directions. Screw will move on the Threads provided in the vice.


There is a pair of jaw is used. between this jaw the specimen is placed. one Jaw is fixed which is placed in the main body part. the other movable jaw is placed in slider which will move along with the slider.


Handle is a part to control the movement of the slider. handle will be rotated to hinge or unhinged The specimen between the Jaws and by the forward and backward motion of the slider. The rotation of the handle will be converted into the sliding movement by the threads.

These are all the main parts of a bench vice. Bench vice is most used holding tool amongst all. Fitter works can not be imagined without it.

What is hammer - Different types off hammer

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Hammer is a hand tool used to provide a sudden impact to an object. hammer is processed by just hitting an object or delivering a blow to it. the plastic deformation can be provided to an object by delivering blow by a hammer. hammer is not always used for plastic deformation. hammers are useful for forging a material. Hammers are available in many shape and sizes.
The hammer are classified by its shape, size, type of purpose by it.

Hammer is considered to be the first well defined mechanical tool in human civilization. It's structure is very simple. Generally it contains two part i.e. Head and a handle. head is a part which has two faces. in most of the hammer types, both faces are of different Shape. In the head a hole is provided in which the handle is inserted. Handle is a wooden rod which is used for gripping the hammer.  
in the recent times market, needs, purposed and research have undergone a huge changes and developments. That's why there are many unconventional types of hammer is available in the market. We are not going to discuss all of them. In this post the traditional types of hammer is discussed  

Classification of Hammer

Hammers are simply classified into two categories
1. Hard Hammer
  1. Ball Peen Hammer
  2. Cross Peen Hammer
  3. Straight Peen Hammer
  4. Claw Peen Hammer or Nail Peen Hammer
  5. Sledge Hammer
2. Soft Hammer
  1. Mallet
  2. Brass hammer
  3. Wooden Hammer

Hard Faced hammer 

Hard hammer are those which is made of tough steel. It can endure higher force or pressure. in fact, it can deliver a massive blow to an object. These hammers can be used for plastic deformation in a material. Hard hammer is important tool for forging Process. there are mainly five types of hard faced Hammer-

1. Ball Peen Hammer

Ball peen hammer two different shapes in both ends of head. one end has a simple faces structure which is round and concave in shape. the other side is one on which the name of the hammer is based. The other end has a ball shaped peen structure. this ball peen structure helps when impact is needed in a single and particular point.

2. Cross Peen Hammer

Cross peen hammer has a wedge shape at one end of its head. The Face of this wedge ii perpendicular to the handle. the other end of the hammer has same concave round shape as in Ball peen hammer. cross peen hammer is useful in metal working processes.

3. Straight Peen Hammer

Straight peen hammer also has wedge shape same as cross peen hammer but its angle will be different the wedge will be parallel to the handle. So the wedge will be rotated at 90 degrees with respect to cross peen hammer. Straight peen hammer is also used for metal working.

4. Claw Peen Hammer or Nail Peen hammer

Claw Peen hammer is used to pull out the nails from an object that has been inserted in that object previously.The head of the claw peen hammer has a pointed element which is also rounded, between that a 'V' shaped space is provided. The nail will be bring between this space and later it will be pulled out. the 'V' shape helps to pull out different sizes of nails.

5. Sledge Hammer

Sledge hammer is a heavy weight tool used for heavy works. both ends of the hammer is same in size. the length of the handle is larger than other hammers. Sledge hammer is used in forging process. It can break or deform metals.

Soft Faced Hammer

Soft faced hammer are those which are made of the material other than steel. less harder material are used in soft hammer. they are generally made up of rubber, plastic, wood, brass etc.


Mallet is a soft faced hammer. its head is made up of non metallic material like rubber, hard plastic etc. this hammer is used to deliver less pressurized blow to an object. As hard hammer can be used for deformation of a material, unlike them soft hammer is used to manage shift or placement of any object at right place without deforming that object. Fitters uses the mallet in the machine or any part where soft blow is required. Generally, both the sides of had same shapes.  

Brass Hammer

Brass hammer is a metallic hammer but here it is classified in soft hammer category because brass hammer can not be used for heavy works like forging. generally brass Hammer is used by gold-smiths to manage tasks with gold. As gold and silver are soft metals so brass hammer is appropriate option to deal with such metals.

Wooden Hammer

The structure and application of wood hammer is same as mallet hammer. the difference is material by which it is made of. instead of rubber or plastic wood is used. carpenters uses this hammer.

Gavel is also a hammer made of wood, gavel is a hammer used by judges in court.

What is a Caliper, What are types of caliper- Define inside and outside caliper

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Calipers are one of the most useful tool in the fitting shop. Caliper is simple measuring tool which is used to measuring distance. Caliper is useful in conjunction with the steel rule because calipers do not contains reading. first the distance is taken by the calipers from the specimen  then the calipers will be shifted to the scale is other measuring tool like micrometer or vernier caliper.
Caliper is a structure in which two legs are used which are riveted together. Generally a screw and nut is provide to the caliper so that the operator can fix the distance taken from the specimen then it is easy to transfer for further measuring. This is done to improve accuracy.

Types of calipers

There are two types of caliper generally in practice outside and  inside calipers to measure external and internal distances.

What is Inside caliper

inside calipers are used to measure the internal distances such af inside diameter of a hollow cylinder. Inside caliper is very useful to measure the distances of restricted areas. Restricted areas are those where steel rule or scale, micrometers can not be uses. For example if we want to measure a small distance inside a machine where scale can not be placed then it is easy to take distance measurement by inside caliper.
Inside caliper

What is Outside Caliper

Outside calipers are used to measure the external distances. to measure external length this tool provide higher accuracy. for example, if we want to measure the length of a block or outside diameter of a sphere or cylinder  this tool helps in precise measurement. This works by same technique as inside calipers. it is also provided  screw and nut to fix the measurement.  large distances can be measured with improved accuracy.
Outside Caliper

These are two main types of calipers. there are other calipers also present which are used for different purposes. some other calipers are Odd-leg caliper, divider caliper etc.

Fitter Tools and equipment used for Fitter work in fitting Workshop

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Fitting shop is the place where the basics of engineering stats. All the basic tools are used in fitter shop. these tools are known as fitter tools. Most of the tools used in fitting tools is hand driven. To understand the base of manufacturing science and production engineering one need to be aware of these tools, there working operations and their uses.

List of fitting Workshop tools

there are many types of fitter tools classified on the basis of their working-

Measuring tool

2. Micrometer
3. Vernier Caliper
4. Steel rule
5. Guages
6. Set square
7. Bevel protractor

Cutting Tools

8. Hacksaw
9. File
10. Chisel
11. Drill
12. Reamer
13. Tap and Die

Non-Cutting Tools

16. Pliers
17. Screw driver
18. Wrench or Spanner
19. Punch
20. Scraper

Holding Tools

21. Vices
22. Clamps

Safety Tools

23. Apron
24. Safety goggles

Miscellaneous Tools 

25. Anvil
26. Surface Plate
27. V- Block
28. Level Spirit

What is Gyroscope - Gyroscopic couple, Precession and Application

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Gyroscope is a tool to measure and stabilize angular velocity. In the Gyroscope a spinning wheel is used which is free to move and assume any axis. This happens because of conservation of angular momentum. Due to angular momentum, the wheel constantly moves unless any external affect is applied. Gyroscope is used in many Places to maintain and guide rotation.

In the recent technological development there are other types of gyroscope has invented which works on other principles. the electronic, fiber optical etc are the modern types of gyroscope that are being used.

What is Gyroscopic Precession

When a wheel rotates about an axis, the change in its orientation i.e. The angular shift in the axis of rotation is called precession. This angular shift can be determined as the axis of rotation is  itself rotating about the axis of precession. the change in orientation happens when an external force is applied to the gyroscope. The wheel will precess in the direction perpendicular to the direction at which force is applied.
Gyroscopic Couple

Gyroscopic Couple

When a wheel or disc is rotated or spin with a torque about an axis  and with an angular velocity, a centrifugal force reacts on the system. this force create a reactive torque which has another axis perpendicular to the axis in which the disc is rotating. Due to this the axis of rotation will precess or turn at an angle. the turning of the wheel depends on its direction of rotation whether it is clockwise or anticlockwise.

if the wheel rotate about axis OX  at anticlockwise direction, the couple will act at the axis of couple. due to this couple the the wheel will move along the plane of precession with an angle. the plane of precession will be perpendicular to the axis of precession.

What are different types of Casting defects - Causes and Remedies

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1. Mould Shift or mismatch

In The sand casting when upper and lower part do not aligned together properly, the path will be shifted from it's desired position. it causes due to inappropriate making or preparation of mould cavity.


1. Misalignment of cope and drag part of mould cavity while preparing mould. Samsung
2. defective tools used for preparation which causes the improper making of mould cavity.


That tools should not be defective and should align properly.
2. The Cope and drag part should be mounted properly.
3. Correct placement of the pattern.
4. Molten material should be poured carefully.

2. Misrun

Sometimes when the molten metal is poured in the cavity, the solidification of the metal takes place in a quick manner. the metal solidifies so quickly that the metal can't occupy the whole cavity and some part of the cavity is not filled by the molten metal. this defect is known as mis- Run


1. Narrow parts of sections of the mould.
2. Low temperature of molten metal.


1. Narrow sections should be avoided otherwise temperature of the molten metal should be sufficient for these fractions.
2. Temperature and fluidity should be analysed. If we keep these two factors correct the problem of Misrun can be overcome.

3. Cold shut

This defect in casting often occurs when two gates to pour the molten metal is employed. when molten material is filled with two gates the material meets inside the cavity. at the place of junction, a proper fusion of these materials is required. if the temperature of the metal is not appropriate, the fusion of the molten metal can be improper. a line or edge at the junction will be formed this line or edge indicates the defect of cold shut in the casting.


1. Low Temperature of molten metal
2. Lack of fluidity of molten metal.


1. Higher temperature of molten metal should be achieved
2. Fluidity of the metal should be controlled by pressure and temperature.

4. Shrinkage of molten metal

After Pouring the molten metal solidification takes place. During  the solidification the shrink in the material occurs, and because of this shrinkage in the metal the cavity is not filled up to the requirement and casting remains shorter.


1. Higher temperature of the metal is main reason behind this defect.
2. Miscalculation of allowances.
3. Improper solidification of molten metal


1. Shrinkage allowance should be provided to the pattern during its preparation.
2. The temperature of molten metal should not be very high.

5. Microporosity

This defect is hard to detect as it occurs at microscopic level. But this weakens the final casting. This porosity left when the solid station is about to be completed. It generally occurs at near the walls or sand edges the microporosity is detected product undergo for testing processes.


1. Higher solidification time.
2. Gases  entrapped in the cavity.


1. Solidification time should be reduced.
2. Gating system should be improved for the gases to be removed from the cavity.

6. Metal Penetration

This defect takes place when the grain size of the casting sand is thick. The molten metal combines or fused together with the sand at the surfaces. This results the surface to be very rough and uneven. The appearance of the product is bad.


1. Large or thick size of sand grains.
2. Improper ramming of sand while preparing mould.
3. Lower strength of the sand.
4. Temperature of the molten metal aise high


1. Casting sand of fine grain size should be used.
2. The extra material due to metal penetration on the surfaces can we chipped off later.
3. Higher temperature should be avoided.
4. Ramming of the moulding sand should be proper.

7. Blow holes

The mould cavity contains some gases inside before pouring the molten metal. When we pour the molten metal some part of these gases get entrapped inside the material. After solidification of molten metal the round cavities is formed on the surface of the final product these cavities are called blowholes.


1. Sand is rammed to hard.
2. Sand contains excess moisture
3. The grains of sand is too fine.
4. Inappropriate use of organic binders
5. Venting of the mould is not proper.
6. The tools like chills, chaplets contains moisture.


1. Ramming of the mould should be less hard.
2. Excess moisture should be removed from the sand.
3. Use the sand of thicker grains.
4. Proper venting should be provided to the mould.
5. The tools used like chills and chaplets should not have impurities.