Hacksaw – Types and Uses in ITI Turner Trade

In the ITI Turner trade, cutting tools are essential for shaping and preparing workpieces before machining operations. One of the most commonly used hand cutting tools in workshops is the hacksaw. It is widely used for cutting metal, plastic, and other materials. This chapter explains the construction, types, blades, and uses of hacksaws in detail.

Introduction to Hacksaw

A hacksaw is a hand tool used for cutting metals and other hard materials. It consists of a frame that holds a thin blade under tension. The blade has fine teeth that cut the material when moved back and forth.

Hacksaws are commonly used in workshops for cutting rods, pipes, bars, and sheets.

Construction of Hacksaw

A hacksaw consists of the following main parts:

• Frame: Holds the blade in position
• Blade: The cutting part with teeth
• Handle: Used to grip and control the saw
• Tension Screw/Pin: Used to tighten the blade

The blade is fixed in the frame and tightened properly to ensure effective cutting.

Types of Hacksaw Frames

1. Fixed Frame Hacksaw

In this type, the frame has a fixed length and can hold a blade of a specific size only (usually 300 mm). It is simple and commonly used.

2. Adjustable Frame Hacksaw

This type allows adjustment of the frame length, so different sizes of blades can be used. It is more flexible and widely used in workshops.

Hacksaw Blade

The blade is the most important part of the hacksaw. It is made of high carbon steel or high-speed steel and has teeth on one edge.

Types of Hacksaw Blades

• All Hard Blade: Entire blade is hardened; used for heavy work
• Flexible Blade: Only teeth are hardened; less likely to break

Teeth Per Inch (TPI)

Hacksaw blades are classified based on the number of teeth per inch:

• 14 TPI: For soft and thick materials
• 18 TPI: For medium thickness
• 24 TPI: For thin materials
• 32 TPI: For very thin sheets and pipes

Selecting the correct TPI is important for efficient cutting and longer blade life.

Direction of Teeth

Hacksaw blades are usually set with teeth pointing forward. Cutting occurs during the forward stroke, so pressure should be applied only in that direction.

Uses of Hacksaw

Hacksaws are widely used in workshop operations:

• Cutting metal rods, bars, and pipes
• Cutting sheets and plates
• Removing excess material
• Preparing workpieces for machining

Method of Using Hacksaw

Proper technique is important for effective cutting:

• Fix the workpiece securely in a vice
• Select the correct blade
• Hold the hacksaw firmly with both hands
• Apply pressure during forward stroke only
• Use long, steady strokes

Advantages of Hacksaw

• Simple and easy to use
• Low cost
• Suitable for different materials
• Portable and convenient

Limitations of Hacksaw

• Time-consuming for large workpieces
• Requires manual effort
• Less accurate compared to machine cutting

Precautions While Using Hacksaw

Safety precautions should always be followed:

• Ensure blade is properly tightened
• Use correct blade for material
• Wear safety goggles
• Do not apply excessive force
• Keep hands away from cutting area

Maintenance of Hacksaw

• Clean after use
• Replace worn or broken blades
• Store in a dry place
• Keep frame and handle in good condition

Application in Turner Workshop

In the Turner trade, hacksaws are used for cutting raw materials to required sizes before machining. They are also used for trimming and preparing workpieces.

Proper use of hacksaw ensures better efficiency and reduces material wastage.

Conclusion

The hacksaw is an essential cutting tool in the ITI Turner trade. Understanding its types, blades, and uses helps trainees perform cutting operations efficiently.

By selecting the correct blade and using proper techniques, workers can achieve accurate and smooth cuts.

In conclusion, mastering the use of hacksaw is important for every Turner, as it forms the foundation of many workshop operations.