what is chisels? types, definition, uses useful Important fact

Chisels

A chisel is a very simple but powerful tool. It is mostly used to cut light and thin metal sheets. You can think of it like a strong metal stick that helps in cutting other metals.

Chisels are made from high carbon steel. This steel is strong and tough, which makes the chisel strong too. The shape of the chisel can be round, hexagonal (like a nut), or octagonal (like an 8-sided pencil). There is no fixed size for a chisel. Big or small, it is made as per the need.

The chisels are made using a method called forging, where hot metal is shaped by hammering. Its top part, called the striking head, is shaped like a cone at around a 70° angle. This is the part where we hit it with a hammer.

The bottom part of the chisel is shaped like an upside-down rectangular pyramid. This sharp edge is used for cutting. The angle of this cutting edge is usually between 35° and 70°. The angle changes depending on the kind of metal we want to cut.

• If the metal is soft, the cutting edge is made at a smaller angle.
• If the metal is hard, the angle is made larger to cut it properly.

A chisel has three main parts:

1. Head – the top part where the hammer strikes.
2. Body – the middle part which is held in hand.
3. Cutting edge – the bottom part used for cutting.

To make the cutting edge strong and long-lasting, it is heated and then cooled in a special way. This process is called heat treatment, and it includes hardening and tempering.

Types of Chisels

Chisels come in different shapes. Each one is made for a special kind of work. Let’s learn about them: there are some types of chisels.

1. Flat Chisel
   This chisels has a straight cutting edge. It is used to cut flat surfaces and remove big pieces of metal.
2. Cross Cut Chisel
   This one has a narrow edge. It is used to cut narrow grooves or slots in the material.
3. Diamond Point Chisel
   The tip of this chisel looks like a diamond. It is great for making sharp corners or small holes.
4. Semi-Circular Chisel
   This chisel has a curved edge. It is used to make round or curved shapes.
5. Cow-Face Chisel
   This chisel has a wide and rounded face, like a cow’s mouth. It is used to shape smooth, wide surfaces.
6. Hollow Chisel
   This one is hollow inside. It is used to make deep holes or special shapes that are hard to do with other chisels.
7. Offset Chisel
   The cutting part of this chisel is slightly bent or set to one side. It is used to work in places where a straight chisel can’t reach.
8. Web Chisel
   This chisel is thin and strong. It is used for fine work and cutting small, detailed areas.
   
   

(i) Flat Chisel

A flat chisel is wide and flat. Its cutting edge is slightly rounded, which helps it cut metal more easily.
This is the most commonly used chisel. It is used to remove metal by cutting small pieces called chippings.

🛠️ Use:
It is used in many different jobs to cut or shape metal.

(ii) Cross Cut Chisel

A cross cut chisel has a narrow cutting edge. Its width is less than its thickness.
This chisel is used to cut grooves or deep lines in metal. It is also used to make key-ways in shafts or key-hubs.

💡 A groove is like a long narrow cut.

You can also make a half-round groove by shaping one end of this chisel in a rounded form.

🛠️ Use:
Cutting deep grooves and key-ways.

📸 Picture of Cross Cut Chisel

(iii) Diamond Point Chisel

This chisel has a sharp point shaped like a diamond. Its edge is pointed and square.
It is used to cut ‘V’-shaped grooves. It is also helpful in sharpening the corners of rectangular grooves.

🛠️ Use:
Making V-shaped cuts and cleaning up sharp corners.

(iv) Half Round Chisel

The front part of this chisel is shaped like a half-circle. It has a small cutting edge at the tip.
It is used to make key-ways inside round parts like hubs. It is also used to cut small oil grooves inside machine parts like brushes.

🛠️ Use:
Cutting curved grooves and oil paths.

📸 Picture of Half Round Chisel

Cow-Mouth Chisel

A cow-mouth chisel has a hollow shank, and the front part is slightly narrow or tapered. If you look at its cutting edge, it looks like the open mouth of a cow — that’s why it’s called a cow-mouth chisel.

This chisel has a curved edge on the inside. It is specially made to cut things that are round or circular in shape. It works well when you need to shape the outside edge of any round object.

Cutting edge: Curved like a cow’s mouth.
Use: For cutting around the edge of round or curved surfaces.
Looks like: Cow-head from the front.

Hollow Chisel

A hollow chisel is also hollow, just like the cow-mouth chisel. But its front part is cone-shaped — like a small round tunnel. Its cutting edge is round or circular, as shown in the picture.

This chisel has a small slit above the cutting edge. When you use it, the unwanted material comes out from this slit. It is very useful for making neat, round holes.

It is mostly used to cut soft things like soft metals, rubber sheets, leather, and similar materials.

Cutting edge: Round and sharp.
Use: For making round holes.
Works on: Soft metals, rubber, leather, etc.
Special feature: Slit helps remove scrap material.

Web Chisel

A web chisels is a special tool. It is used after drilling holes in metal. When we make two or more holes close to each other, there is a small piece of metal left between them. This piece is called the web. A web chisel helps us to cut and remove that metal in between, making the space smooth and clean.

Just like we use an eraser to clean pencil marks, we use a web chisel to clean the leftover metal between drilled holes.

Cutting Angles for Chisels

Chisels are made for cutting different types of metals. For this, we need to keep the cutting angle correct.

Here is a simple rule:

• Most chisels have a cutting angle of 60°.

This angle helps the chisel cut the metal smoothly without breaking or getting damaged.

Different chisels may have different angles based on what metal they are used for — but 60° is the most common.

there are some types of chisels.

Precautions While Using Chisels

Using a chisel is simple, but if you’re not careful, it can be dangerous. That’s why it’s important to follow some easy and smart rules. These rules will help you stay safe and also take care of your tools.

Right Angle Matters
The cutting angle of the chisel should match the metal you are working on. Every metal is different, so using the right angle helps cut better and smoother.

Keep the Edge Slightly Curved
The tip of the chisel should be a little round, not flat. This makes the chisel last longer and helps in cutting the metal more easily.

Fix Worn-Out Heads
If you use a chisel for a long time, its head may get damaged. If you see it becoming rough or cracked, grind it properly. If not, it might break and hurt someone.

No Grease or Oil
The hammer and the chisel head must be clean and dry. If there is grease, the hammer might slip and cause an accident.

Always Use a Guard
When you are chipping, always use a hand guard. It protects your hands from flying metal pieces or wrong hammer hits.

Keep Your Eyes on the Blade
While working, always look at the sharp edge of the chisel. Don’t look at the top or get distracted. This helps you work more accurately and safely.

Don’t Use a Blunt Chisel
A blunt chisel makes the work harder and can also slip. Always use a sharp chisel for clean and easy cutting.

Chip in the Right Direction
Always chip from the moving jaw to the fixed jaw. This gives better control and reduces the risk of slipping.

The calculation of chisels

1. Chisel Quantity Calculation
   Are you trying to calculate how many chisels are needed for a construction or manufacturing project?
2. Material Calculation for Making a Chisel
   Do you want to calculate how much steel or other material is needed to manufacture a chisel?
3. Force or Cutting Power Calculation
   Are you looking to calculate the force, angle, or cutting power related to using a chisel?
4. Cost Calculation
   Are you trying to estimate the total cost of purchasing or manufacturing chisels?

Example: Material Calculation for Making a Chisel

If you’re calculating the volume of material needed to make a chisel, you can use this formula:

Volume (V) = Length × Width × Thickness
(assuming a rectangular bar for simplicity)

Then, if you’re using steel:

Weight = Volume × Density of steel (≈ 7.85 g/cm³ or 7850 kg/m³)

FAQ