GRINDER AND GRINDING MACHINES

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• Q1: Define a Grinder.
  Ans: A grinder is a machine tool used to remove small amounts of material from a workpiece by using an abrasive rotating wheel for finishing the surface.
• Q2: What is a Grinding Machine?
  Ans: A grinding machine is a power-operated machine that uses a rotating grinding wheel to cut, shape, or finish metal and other materials with high accuracy.
• Q3: State the parts of a Grinding Machine.
  Ans: The main parts of a grinding machine are:

  • ➔ Base
  • ➔ Table
  • ➔ Wheel Head
  • ➔ Grinding Wheel
  • ➔ Work Holding Device
  • ➔ Motor
• Q4: State four uses of Grinding Machine.
  Ans: Uses of grinding machine are:

  • ➔ To finish surfaces
  • ➔ To sharpen cutting tools
  • ➔ To remove small amounts of material
  • ➔ To produce accurate dimensions
• Q5: What is a Utility Grinder?
  Ans: A utility grinder is a general-purpose grinding machine used for performing different types of grinding operations such as sharpening and finishing.
• Q6: State the types of Utility Grinder.
  Ans: Types of utility grinders are:

  • ➔ Bench Grinder
  • ➔ Pedestal Grinder
  • ➔ Portable Grinder
  • ➔ Wet Grinder
• Q7: Briefly explain the Bench Grinder.
  Ans: A bench grinder is a small grinding machine mounted on a workbench. It is used for light grinding, sharpening tools, and finishing small jobs.
• Q8: Briefly explain the Pedestal Grinder.
  Ans: A pedestal grinder is a heavy-duty grinding machine mounted on a stand (pedestal). It is used for heavy grinding work and larger tools.
• Q9: Briefly explain the Portable Grinder.
  Ans: A portable grinder is a handheld grinding machine that can be carried easily. It is used for grinding at different locations and for repair work.
• Q10: Briefly explain the Wet Grinder.
  Ans: A wet grinder is a grinding machine that uses water or coolant during grinding. It helps to reduce heat and improves the surface finish.
• Q11: What are Grinding Wheels?
  Ans: Grinding wheels are circular tools made of abrasive grains bonded together, used in grinding machines to cut, shape, or finish materials.
• Q12: What is a Binding Material? Name some.
  Ans: Binding material is the substance that holds the abrasive grains together in a grinding wheel.
  Examples are:

  • ➔ Clay
  • ➔ Resinoid
  • ➔ Rubber
  • ➔ Shellac
• Q13: Define Grade.
  Ans: The force that connects or joins abrasive grains is called grade.
• Q14: Define Abrasive Grains.
  Ans: Abrasive grains are small, hard particles used in grinding wheels to remove material from the surface of a workpiece.
• Q15: Name the types of Abrasives.
  Ans: Types of abrasives are:

  • ➔ Natural Abrasives
  • ➔ Artificial Abrasives
• Q16: What are Natural Abrasives? Name some.
  Ans: Natural abrasives are obtained from nature.
  Examples are:

  • ➔ Emery
  • ➔ Quartz
  • ➔ Diamond
• Q17: What are Artificial Abrasives? Name some.
  Ans: Artificial abrasives are made by humans in factories.
  Examples are:

  • ➔ Silicon Carbide
  • ➔ Aluminium Oxide
• Q18: Define Resinoid Bonds.
  Ans: Resinoid bonds are made from synthetic resins and provide high strength and flexibility to the grinding wheel.
• Q19: Define Rubber Bonds.
  Ans: Rubber bonds use rubber as a bonding material and provide smooth finish and flexibility.
• Q20: Define Shellac Bonds.
  Ans: Shellac bonds use shellac as a bonding material and are used for fine finishing work.
• Q21: Define Silicate Bonds.
  Ans: Silicate bonds use silicate material and are used where low heat generation is required.
• Q22: Define Vitrified Bonds.
  Ans: Vitrified bonds are made from clay and ceramic materials and are strong, rigid, and commonly used in grinding wheels.
• Q23: State the selection criteria of the Grinding Wheel.
  Ans: Selection of grinding wheel depends on:

  • ➔ Type of material
  • ➔ Type of grinding work
  • ➔ Wheel speed
  • ➔ Surface finish required
  • ➔ Type of machine
• Q24: What is the Grain Structure in a Grinding Wheel?
  Ans: Grain structure refers to the spacing between abrasive grains in a grinding wheel. It may be dense or open depending on the requirement.
• Q25: State the types of Grinding Wheels.
  Ans: Types of grinding wheels are:

  • ➔ Straight Wheel
  • ➔ Cylindrical Wheel
  • ➔ Saucer Wheel
  • ➔ Dish Wheel
  • ➔ Tapered Wheel
  • ➔ Straight Cup Wheel
• Q26: What is a Straight Type Wheel?
  Ans: A straight wheel is a common grinding wheel with a flat surface used for general grinding purposes.
• Q27: What is a Cylindrical Type Wheel?
  Ans: A cylindrical wheel is used for surface grinding and has a large contact area with the workpiece.
• Q28: What is a Saucer Type Wheel?
  Ans: A saucer wheel is shaped like a saucer and is mainly used for sharpening cutting tools.
• Q29: What is a Dish Type Wheel?
  Ans: A dish wheel has a concave shape and is used for tool and cutter grinding.
• Q30: What is a Tapered Type Wheel?
  Ans: A tapered wheel has a tapered shape and is used for special grinding operations.
• Q31: What is a Straight Cup Type Wheel?
  Ans: A straight cup wheel is cup-shaped and is used for surface grinding and tool sharpening.
• Q32: State the safety precautions for Grinding.
  Ans: Safety precautions are:

  • ➔ Wear safety goggles
  • ➔ Check the grinding wheel before use
  • ➔ Do not use damaged wheels
  • ➔ Keep proper distance from wheel
  • ➔ Use proper guards
  • ➔ Avoid loose clothing