TYPES OF DRILLS

Mansoura UniversityFaculty of Engineering

Dept. of Production Engineering and Mechanical

Design

Machining Techniques and Equipment (1) - Types of Drills 2

PRESENTED BY:Hassan NabilMohammed MegahedSameh MohammedMostafa SadekHossam Sobh

SUPERVISED BY:Dr. Rania Mostafa

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OUTLINE:• What is a drill?• Why need different types of

drills?• What changes from one type of

drills to another?• Introducing different types of

drills.• Conclusion

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INTRODUCTIONWhat is a drill?• A drill is, mostly, a double-edged

cutting tool, used for producing circular holes in the work-piece.

• There is a variety of purposes for which circular holes are needed, such as fitting joints or shafts or even passing gases, fluids, etc.

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WHY NEED DIFFERENT TYPES OF DRILLS?

• Obviously, the various purposes of circular holes leaded to a wider variety in the types of drills.

• Each drill is specialized in making a hole with specific characteristics which cannot be obtained using another drill.

• For examples, drilling in soft materials requires a specific type of drills. One cannot simply completes this mission using a drill that is specialized in widening holes!

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WHAT CHANGES FROM ONE TYPE OF DRILLS TO

ANOTHER?• There are significant characteristics that differ one type of drills from any other type.• The specifications that change may be the tool

material, flute length, diameter, helix angle, point angle, type of shank, etc.• The job required decides on the specifications

needed, that is, a specific type of drills.

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• For example, fast spiral drills are preferred to generate deep holes. Also, reducing the land width increases chip space.

WHAT CHANGES FROM ONE TYPE OF DRILLS TO

ANOTHER?

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DIFFERENT TYPES OF DRILLS

Spade Drill

Gun Drill

Step Drill

Core drill

Twist Drills

General-purpose

drillLow-helix

drillHigh-

helix drillCoolant

hole drill

Straight flute drill

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DIFFERENT TYPES OF DRILLS

Step Drill

Spade Drill Core Drill Straight-

Flute DrillGun Drill

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DIFFERENT TYPES OF DRILLS

TWIST DRILLS:• Twist drills are the most common drills in

use.• In the following slides comes a very brief

introduction to some of twist drills.

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TWIST DRILLS:

DIFFERENT TYPES OF DRILLS

1. General-Purpose Drill:• Has two Helical flutes.• Designed to perform well on wide variety of materials, equipment and job conditions.• Comes in varying point angle, speeds and feeds to be suitable for many conditions.

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TWIST DRILLS:

DIFFERENT TYPES OF DRILLS

2. Low-Helix Drill:• Developed primarily to drill brass and thin materials.• Used to drill shallow holes in some aluminium and magnesium alloys.• Can remove large volume of chips formed by high rates of penetration.

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TWIST DRILLS:

DIFFERENT TYPES OF DRILLS

3. High-Helix Drills:• Designed for drilling deep holes in

aluminium, copper, die-cast material, and other metals.

• High helix angle (35º to 45º).• Wider flutes assist in clearing chips

from hole.

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TWIST DRILLS:

DIFFERENT TYPES OF DRILLS

4. Oil Hole Drills• Have one or two oil holes running from

shank to cutting point in order to force compressed air, oil, or cutting fluid while deep holes are being drilled.

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CONCLUSION…

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THANK YOU!