Vee Block, Scribing Block and Straight Edge – Types and Uses in ITI Turner Trade

In the ITI Turner trade, marking and measuring tools play a crucial role in ensuring accuracy and precision in machining operations. Tools such as the vee block, scribing block, and straight edge are commonly used for holding, marking, and checking the alignment of workpieces. This chapter explains their construction, types, and applications in workshop practice.

Introduction to Marking and Supporting Tools

Marking and supporting tools are used to assist in layout work and measurement processes. They help in positioning the workpiece correctly and ensure that marking lines are accurate and precise.

In a Turner workshop, these tools are widely used before machining operations begin.

Vee Block

A vee block is a precision tool used to hold cylindrical workpieces securely. It has a V-shaped groove that supports round objects such as shafts and pipes.

Construction of Vee Block

The vee block is made from cast iron or hardened steel. It has a V-groove, usually at 90°, and a flat base. It is often used with a clamp to hold the workpiece firmly.

Types of Vee Blocks

• Single Vee Block: Has one V-groove
• Double Vee Block: Has two V-grooves for different sizes
• Magnetic Vee Block: Uses magnetic force to hold workpieces

Uses of Vee Block

• Holding cylindrical workpieces
• Marking lines on round surfaces
• Checking alignment and parallelism
• Supporting work during drilling and machining

Scribing Block

A scribing block is a marking tool used to draw lines on a workpiece at a specific height. It is commonly used along with a surface plate.

Construction of Scribing Block

The scribing block consists of a heavy base, a vertical rod, and an adjustable scriber. The base ensures stability, while the scriber is used for marking lines.

Types of Scribing Blocks

• Simple Scribing Block: Basic design with fixed scriber
• Universal Scribing Block: Adjustable scriber for different angles and heights

Uses of Scribing Block

• Marking horizontal lines on workpieces
• Transferring measurements
• Checking flatness and alignment
• Layout work on surface plate

Straight Edge

A straight edge is a measuring tool used to check the straightness and flatness of surfaces. It is a simple tool but very important for inspection work.

Construction of Straight Edge

Straight edges are made from steel or cast iron. They have a perfectly straight working edge used for checking surfaces.

Types of Straight Edges

• Metal Straight Edge: Used in machining and engineering work
• Precision Straight Edge: High accuracy tool for inspection
• Bevel Edge Straight Edge: Used for checking narrow surfaces

Uses of Straight Edge

• Checking flatness of surfaces
• Checking straightness of edges
• Aligning machine components
• Inspection of finished workpieces

Advantages of These Tools

• Provide accurate marking and measurement
• Improve quality of work
• Easy to use and maintain
• Essential for layout and inspection work

Limitations

• Require proper handling to maintain accuracy
• Not suitable for direct measurement of dimensions
• Depend on user skill

Precautions While Using

To ensure accuracy and safety, the following precautions should be taken:

• Keep tools clean and free from dust
• Handle carefully to avoid damage
• Use proper clamping with vee block
• Do not drop or mishandle precision tools

Maintenance of Tools

• Clean after use
• Apply oil to prevent rust
• Store in proper place
• Check accuracy regularly

Application in Turner Workshop

In the Turner trade, vee blocks are used for holding cylindrical workpieces during marking and machining. Scribing blocks are used for marking reference lines, and straight edges are used for checking alignment and flatness.

These tools help in achieving precision and accuracy, which are essential for quality machining.

Conclusion

Vee blocks, scribing blocks, and straight edges are essential tools in the ITI Turner trade. They assist in marking, holding, and inspecting workpieces, ensuring accuracy and efficiency in workshop operations.

Understanding their construction, types, and uses helps trainees perform tasks effectively and maintain high standards of work.

In conclusion, these tools play a vital role in achieving precision and should be used with care and proper technique.