Mastering Broaching: The Machining Process, Applications, and Advantages

Broaching is a careful and quick way to cut metal parts, utilizing the broaching process to create hard shapes in just one step. This method is special because it provides very exact cuts and produces smooth surfaces faster than milling or grinding. Many companies choose the broaching process when they need to manufacture large quantities of parts.

The market for broaching machines was US$ 312.6 million in 2024. It may grow to US$ 473.1 million by 2031. This indicates a strong demand for better methods to work with metal.

What Is Broaching?

Definition and Purpose

Broaching is used to shape metal parts fast and accurately. The broaching tool has many cutting teeth. It removes metal in one smooth movement. This helps make shapes like splines, keyways, and gears in one go. Factories use broaching when they need to make lots of parts. Broaching can do rough and fine cuts at the same time. This saves time and work.

Broaching helps you get exact sizes and smooth surfaces fast. You do not have to change tools for rough or fine cuts. Broaching is great for making many parts that must fit together well.

Here is a table that shows how broaching is used in different industries:

Key Features

Broaching has many benefits over other ways to cut metal. The tool has rough, semi-finish, and finish teeth. These teeth work together to make a smooth surface and exact size in one stroke. You do not need extra finishing steps. Broaching is special because it makes detailed shapes with high accuracy and speed. It works for both small and big parts. Broaching is good for making lots of parts.

• Broaching makes shapes like gears and splines more accurately than milling.

• It removes metal fast and keeps tight size limits.

• Broaching is good for parts that need a perfect fit and smooth finish.

Tip: If you need to make many parts with hard shapes, broaching can help you save time and make better parts.

Broaching Process Overview

Broaching uses a tool with many teeth. This tool removes metal in one smooth pass. You can make hard shapes fast and with good accuracy. Let’s look at how broaching works and the main types.

Linear vs. Rotary Broaching

There are two main broaching types: linear and rotary. Each type works best for certain jobs.

Linear broaching moves the tool straight through the part. You use it for keyways, splines, and straight shapes. It lets you control how deep and thick each cut is.

Rotary broaching spins the tool as it pushes into the part. This way, you can make hexagons or splines on round pieces very fast. You do not need to change setups, so you save time and money. Rotary broaching is great for making lots of parts with the same shape.

Tip: Rotary broaching helps you make shapes on round parts quickly. You can finish more parts with less work.

Internal and External Broaching

Broaching can cut inside or outside surfaces. Internal broaching shapes the inside of holes or spaces. You use it for keyways or splines inside gears and pulleys. Internal broaching machines are very exact and work well for tight fits.

External broaching shapes the outside of a part. You use it to cut flat areas, slots, or special shapes on shafts and other pieces. Both types give smooth finishes and exact sizes in one pass.

Here is a simple guide for broaching:

1. Put the part in place and hold it tight.

2. Pick the right broach tool for the job.

3. The tool moves through or over the part. Each tooth cuts a little bit.

4. Keep going until you get the final shape and size.

5. Take out the finished part. It usually does not need more cutting.

Broaching works well for parts that need to be very exact and smooth. Car and airplane makers use broaching for these reasons.

Tools and Equipment

The tools and machines you use matter a lot in broaching. The broach tool’s design changes how much metal you can cut and how smooth the part will be. You can pick different tool materials and coatings for your needs. Some coatings help tools last longer and cut better.

Modern broaching machines use CNC controls. This lets you set the best speeds and change shapes without stopping. New machines use electric drives instead of big hydraulic systems. These changes make broaching faster and easier to control.

Note: Check and clean your broaching machines often. Oil moving parts and look for damage to keep things working well.

Broaching tools and machines are used in many places. Car makers use them for engine parts. Airplane companies use them for exact pieces. Machine makers use broaching for gears and seats.

If you want to get good at broaching, you should learn and practice. Training helps you use machines safely and get the best results. Many people learn by doing, taking online classes, or reading about broaching.

Broaching Applications

Automotive Applications

Broaching is used a lot to make car parts. Car makers use it to shape gears and shafts. These parts need to be the right size. Broaching helps parts fit together well. It also makes sure they work smoothly. Broaching can make many parts fast. It does not lose accuracy when making lots of parts.

• Broaching shapes gears and shafts for cars.

• You can use broaching to make high-precision parts.

• The process works well for parts that need tight tolerances.

There are different broach tools for each job. Keyway broaches cut slots inside gears. Splined broaches make teeth or notches. These tools help parts last longer. They also help parts work better.

Aerospace and Defense

Broaching is important for airplane and defense parts. These parts must be strong and exact. Broaching on CNC lathes cuts keyways and slots. It works on hard metals like Inconel. Broaching can reach very tight sizes, like 0.004 inch. This is needed for safety and good performance.

• Broaching creates keyways and slots in aerospace parts.

• You can use broaching for hard metals, such as Inconel.

• The process gives you the accuracy needed for flight and defense systems.

Broaching is used for simple and complex shapes. It helps meet strict rules. It also helps keep costs low.

Other Industries

Broaching is not just for cars or planes. Many other industries use broaching to make better products. It also helps save time.

You might wonder about broaching. Many people ask about fixing problems and tool types. They also ask how to use broaching with CNC machines. You can pick from keyway, square, hexagonal, round, or splined broaches. The right tool and good care help you get the best results.

Tip: Broaching is a good way to make strong and exact parts. It helps you reach your goals for quality and reliability.

Advantages of Broaching

Precision and Surface Finish

Broaching gives you very exact parts. The broaching tool has many teeth. It cuts the metal in one go. This makes the part the right size and shape. The surface is very smooth, even smoother than with other methods.

• Drag finishing in broaching makes the surface less rough.

• The roughness drops a lot for Ra and Rz, more than with grinding.

• Broaching helps you get tight fits and smooth parts, which is needed for gears and airplane parts.

Quality control is very important. You use good machines and strong clamps. You also pick the best cutting tools. You set the right depth and speed for each job. These steps help every part meet the needed rules.

Efficiency and Speed

Broaching is much faster than other ways to cut metal. You can finish parts quickly.
Here is a table that shows how broaching is faster than CNC machining:

Broaching can go from 20 to 120 SFPM. The cycle can be as short as 5 to 30 seconds. This saves time and helps you make more parts. Broaching tool design also helps you work better and get good results.

• Broaching gives you more parts and better quality.

• Good tool design makes your job faster and easier.

Cost and Durability

Broaching helps you save money, especially when making lots of parts. It uses less energy and needs fewer extra steps. Broaching tools last longer if you use them right.
Broaching tools wear out in special ways. You need to check for wear, chips, or breaks. These problems can make the surface bad and cause you to throw away parts. Tool life is very important for expensive things like turbine discs.

You can make broaching better for the planet. Dry broaching with coated tools works three times better than old ways. Using less oil can cut CO2 by up to 21%. Sharpening tools again lowers global warming by 81% and saves 66% of fossil fuels.

Tip: Pick the best broaching process and take care of your tools. This helps you work faster and save money.

You now know that broaching shapes metal parts quickly and accurately. This process is important in making things today, like cars and airplanes. Studies show broaching helps make very exact parts and works well with machines. But it can cost a lot and needs skilled people to run it. If you want to use broaching, check out these expert tips:

Learn more about broaching to get better results in making things.

FAQ

What materials can you broach?

You can broach metals like steel, aluminum, brass, and some plastics. Harder metals need special broaching tools. Always check if your material matches the tool’s strength.

How do you keep broaching tools sharp?

You should clean and inspect your broaching tools often. Sharpen them when you see dull edges or rough finishes. Sharp tools help you get better results and longer tool life.

Can you use broaching for small parts?

Yes, you can broach small parts. Use the right broach size and machine settings. Small parts need careful handling to avoid damage.

What shapes can you make with broaching?

• You can make:

• Keyways

• Splines

• Hexagons

• Squares

• Special profiles

Broaching lets you create many shapes in one pass.