Cutting and Driving Tools: Metal Work Hand Tools – JSS1 Basic Technology Lesson Note (Third Term)

Metalwork hand tools are grouped into cutting tools and driving tools.

Behavioural objectives

By the end of the lesson, students should be able to:

1. define cutting tools and driving tools and name examples of each;
2. describe the hacksaw and state its types;
3. state the grades and types of file and the uses of each;
4. state the types of chisel and scraper and their uses;
5. state the types of hammer, punch and screwdriver and their uses.

What are cutting tools?

Cutting tools are tools used for cutting materials by sawing, filing, chiselling and scraping.

• Hacksaw: cuts metals by sawing.
• Files: shape and finish metals by filing.
• Chisel: shapes metals by chipping.
• Scraper: removes imperfections from a worked surface.

What is a hacksaw?

A hacksaw is a saw used mainly for cutting metals in the metal workshop.

• Frame: holds the blade and carries the handle.
• Blade: the toothed part that does the cutting.

What are the types of hacksaw?

There are three types of hacksaw: adjustable, tubular and junior.

1. Adjustable hacksaw: accommodates blades of different lengths.
2. Tubular hacksaw: has a fixed frame made of tube.
3. Junior hacksaw: used for cutting thin sheets.

What are files?

Files are tools that shape metal by removing it bit by bit.

• Use: finishing jobs to the required size and shape.
• When used: after the job has been cut with a chisel or a hacksaw.
• Material: high carbon steel (hardened and tempered).

How are files classified?

• Length: the size of the file.
• Cross-section: the shape of the file across its width.
• Shape: the outline, such as flat, round or square.
• Grade: how coarse or fine the teeth are.
• Area of cut: the part of the file that carries teeth.
• Nature of teeth: the pattern of the cutting teeth.

What are the grades of file?

There are five grades of file: rough, bastard, second, smooth and dead smooth.

What are the types of file?

There are seven common types of file: flat, hand, round, half-round, triangular, knife-edge and square.

What are the methods of filing?

There are three methods of filing: across from left to right, across from right to left, and draw filing.

• Across, left to right: the file is pushed across the job, moving from left to right.
• Across, right to left: the file is pushed across the job, moving from right to left.
• Draw filing: the file is pushed and pulled along the surface to give a smooth finish.

What is a chisel?

A chisel is a chipping tool used for shaping metals where filing and other finishing methods cannot be used.

• Action: it chips away metal when struck with a hammer.
• Use: shaping metal where finishing by filing cannot be carried out.
• Material: high carbon steel (hardened and tempered).
• Types: flat, cross-cut, round-nose and diamond point.
• Choice: the type used depends on the shape of the cut needed.

What are the types of chisel?

There are four types of chisel: flat, cross-cut, round-nose and diamond point.

What is a scraper?

A scraper is a tool used for removing imperfections from a surface that has been worked on before.

• Material: medium carbon steel (hardened and tempered).

What are the types of scraper?

There are three types of scraper: flat, half-round and triangular.

• Flat scraper: makes a surface accurately flat after machining or filing. It needs a high level of skill.
• Half-round scraper: removes high spots on curved surfaces such as holes, bearings and large bores.
• Triangular scraper: used in awkward corners where the other scrapers are difficult to use.

What are driving tools?

Driving tools are tools used for moving objects into metals by hammering, punching or screw driving.

1. Hammers: drive by striking.
2. Punches: drive by being struck with a hammer.
3. Screwdrivers: drive screws in or out by turning.

What is a hammer?

A hammer is a striking tool made of a metal head and a wooden handle.

• Use: hammers are the most commonly used of all tools.

What are the types of hammer?

There are four types of hammer: ball pein, cross pein, straight pein and mallet.

• Ball pein hammer: the ball end rivets conical-end rivets. The flat end is for striking.
• Cross pein hammer: the pein end rivets in awkward places. The flat end is for striking.
• Straight pein hammer: used for riveting in Vee-grooves.
• Special hammers (mallets): used when a steel head may be too strong for the job.

Mallets are made of lead, copper, rawhide, wood, plastic or rubber.

What is a punch?

A punch is a driving tool used for punching holes in steel metal and for driving out rivets, tapered pins or dowels from holes.

• Pin punch: used for driving dowel pins.
• Round punch: useful when a round sleeve or shaft has to be removed from a hole.
• Square punch: useful where a square bar sleeve has to be removed from its hole.
• Note: all punches do their work with the aid of hammer strikes.

What is a screwdriver?

A screwdriver is a tool used for fixing or removing screws by their heads, using its blade.

• Material: carbon steel (hardened and tempered).

What are the types of screwdriver?

There are four types of screwdriver: flat, star, ratchet and Allen key.

Evaluation

1. Define cutting tools and driving tools.
2. Name the two parts of a hacksaw and state three types of hacksaw.
3. Mention four types of chisel and one use of each.
4. Mention three types of scraper and one use of each.
5. State eight driving tools and one use of each.

Assignment

Name the five grades of file and state the use of each.