5. Marking, cutting and finishing techniques

Talking book

To hold materials in place while we work with them, we use a bench vice, a bar clamp, a C-clamp or a ring clamp. We can also use hand tools such as tongs and pliers.

We use hand and power tools for these techniques. We will look at marking, cutting, drilling, shaping and finishing.

5.1. Marking

Talking book

Centre punch and scriber

The centre punch is used to mark lines and the scriber to mark points on sheets of metal.

How to mark a piece of metal:

Put the centre punch on the point you want to mark and hit the other end of the scriber hard once with a hammer.
Use the scriber to mark straight lines on the metal. You should use rulers and carpenter's rulers like the ones you can see in the pictures.
You can also use dividers to draw lines, circles and arcs, and to transfer measurements.

5.2. Cutting

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Cutter	Guillotine	Punch press and die	Hacksaw
Used to cut soft, flexible, thin sheets of metal. It can cut in straight, angled or curved lines.	Used to cut thin sheets of metal.	Used to cut sheets of 5 mm or thinner. It is used to cut simple pieces to the required shape by bringing the press down against the die.	This has an arc-shaped metal frame, a plastic or metal handle and nuts or wing nuts that hold the blade in place. It's used to cut metal in straight, accurate lines.

Power tools for cutting
Circular saw	Grinder
Used to cut large metal sheets. It can cut along straight or sloping lines.	This has a circular disc that can be used for many things. This tool can be used for cutting, sanding, polishing, planing, removing rough edges, etc. We use different types of discs depending on what we want to do.

5.3. DRILLING

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A router does a lot of the cutting, drilling and cleaning jobs we have studied. A router turns very quickly and shaves off material so we get an excellent finish. Depending on the bit we use, we can make grooves, cuts, teeth and many other shapes.

Awl	Drill
A long piece of metal with a sharp end.	Used to make holes with drill bits.

5.4. Shaping

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Chisel	Lathe
This tool has a double-sided sharp edge. It's used to shape metal by hitting the handle with a hammer and holding it at a 5º angle.	This power tool is used to shape cylindrical objects. It works by turning the object while a blade moves along the length of the object removing the metal.

5.5. Cleaning

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Scraper

This is a small metal, triangular blade with sharp edges. It's used to shave small fragments.

5.6. Power tools for cleaning

Talking book

We use tools and power tools on metal pieces for different operations.
Some of these operations are marking, cutting, drilling, shaping and cleaning.
In all of these operations we have to use the right techniques and follow health and safety rules.

Sander	Grinder
The motor moves the sandpaper, which is made from abrasive material, backwards and forwards rapidly. Sanding is quick and even.	This tool removes material to perfect surfaces. It is very precise and can remove as little as a hundreth of a milimeter of material.