Nomenclature of Drill in ITI Turner Trade

In the ITI Turner trade, drilling is a fundamental machining operation used to create holes in metal workpieces. The efficiency and accuracy of drilling depend on the correct understanding of the drill tool and its parts. The term “nomenclature of drill” refers to the identification and naming of different parts of a drill bit, along with their functions. This chapter explains the various parts of a drill and their importance in detail.

Introduction to Drill

A drill is a cutting tool used to produce circular holes in a workpiece. The most commonly used drill in workshops is the twist drill. It rotates and cuts material using its sharp edges, producing chips.

Understanding the nomenclature of a drill is important for proper use, maintenance, and selection of the tool.

Main Parts of a Drill

1. Shank

The shank is the upper part of the drill that is held in the drill machine. It may be straight or tapered depending on the type of drill.

• Straight Shank: Used in small drills
• Taper Shank: Used in larger drills

2. Body

The body is the main portion of the drill between the shank and the point. It contains flutes and other cutting features.

3. Flutes

Flutes are the spiral grooves on the drill body. They serve several important functions:

• Remove chips from the hole
• Allow cutting fluid to reach the cutting edge
• Help in cutting action

4. Land

The land is the narrow surface between the flutes. It provides support and strength to the drill.

5. Margin

The margin is the outer edge of the land. It helps in guiding the drill and maintaining the diameter of the hole.

6. Web

The web is the central core of the drill. It provides strength to the drill and increases in thickness towards the shank.

7. Point

The point is the cutting end of the drill. It is responsible for cutting into the material.

8. Cutting Edges (Lips)

The cutting edges, also called lips, are the sharp edges at the drill point. They perform the actual cutting operation.

9. Chisel Edge

The chisel edge is the edge formed at the intersection of the two flutes. It does not cut but pushes material aside during drilling.

10. Heel

The heel is the trailing part of the cutting edge. It provides clearance and reduces friction during cutting.

Angles of Drill

1. Point Angle

The angle formed at the tip of the drill is called the point angle. It is usually around 118° for general-purpose drilling.

2. Helix Angle

The angle of the flutes is known as the helix angle. It affects chip removal and cutting efficiency.

3. Clearance Angle

The clearance angle prevents rubbing between the drill and the workpiece.

Functions of Drill Parts

Each part of the drill has a specific function:

• Shank holds the drill in position
• Flutes remove chips
• Lips cut the material
• Margin guides the drill
• Web provides strength

Material of Drill

Drills are made from materials that provide hardness and durability:

• High-Speed Steel (HSS)
• Carbon Steel
• Carbide (for high-speed operations)

Types of Drills

Some common types of drills include:

• Twist Drill
• Flat Drill
• Step Drill
• Core Drill

Importance of Drill Nomenclature

Understanding the nomenclature of a drill is important for:

• Proper selection of drill
• Correct sharpening of cutting edges
• Efficient drilling operation
• Maintenance and inspection

Precautions While Using Drill

• Use correct drill size
• Maintain proper speed and feed
• Use cutting fluid if required
• Ensure proper clamping of workpiece

Application in Turner Workshop

In the Turner trade, drills are used for making holes in workpieces before or after turning operations. Knowledge of drill nomenclature helps in achieving accurate drilling and better surface finish.

It also helps in selecting the right drill and maintaining its performance.

Conclusion

The nomenclature of a drill is an important concept in the ITI Turner trade. Understanding the different parts and their functions helps in efficient and accurate drilling operations.

Proper knowledge of drill nomenclature improves tool handling, maintenance, and overall machining quality.

In conclusion, mastering the drill tool and its parts is essential for every Turner to achieve precision and efficiency in workshop operations.