Additive Manufacturing vs. Subtractive Manufacturing

You can see a big difference between additive and subtractive manufacturing. Additive Manufacturing makes objects by adding layers from digital models. Subtractive manufacturing cuts away material from a solid block to make a shape. Knowing these differences helps you pick the best way for design, speed, and cost. Many workers, companies, and hobbyists use this knowledge.

• The world additive manufacturing market may reach US$ 26.79 billion in 2024.

• Over 4.5 million 3D printing systems may ship this year.

• China may have 57.3% of the East Asia market by 2034.

Additive Manufacturing

How It Works

Additive manufacturing builds objects by stacking layers. You begin with a digital model. The machine follows this model and puts material only where it is needed. This is not like cutting away from a block. Many machines use this way to make things. Here is a table that lists the main technologies:

Materials Used

Additive manufacturing uses many kinds of materials. The most common ones are plastics, metals, and ceramics. Plastics are used the most. They are easy to shape and do not cost much. Metal and ceramic parts are possible too, but they are not as popular. The market for these materials is growing fast and could soon be worth over a billion dollars.

Applications

Additive manufacturing is used in many fields. The table below shows where it is used and what you can make:

Advantages

Additive manufacturing has many good points:

• You do not need to pay a lot at the start. There is no need for special tools or molds.

• You can make custom items easily. Each one can be different without costing more.

• You can make test models fast and start making products quickly.

• You can make small amounts without wasting money.

• You can pick from many materials for different jobs.

Tip: Additive manufacturing is growing quickly. The market could grow by more than 21% each year until 2030.

Limitations

There are some things to watch out for:

• You might waste material if you do not plan well.

• There are fewer material choices than with older ways.

• It is not the best for making huge numbers of items.

• Some surfaces may be rough and need extra work.

• Making very large parts is hard because printers are small.

• You may need extra supports for shapes that are tricky.

Subtractive Manufacturing

How It Works

You make objects by taking away material from a solid block. Machines and tools help you cut, drill, or grind off the extra parts. There are a few main ways to do this:

• CNC Milling: A spinning tool carves shapes from a block.

• CNC Turning: The piece spins while a tool cuts it, often on a lathe.

• Electrical Discharge Machining (EDM): Sparks remove material and help make detailed shapes.

• Waterjet Cutting: A strong stream of water cuts materials and keeps them cool.

• Drilling: Rotating drill bits make exact holes.

Note: Subtractive manufacturing is good for parts that need to be very exact and have smooth surfaces.

Materials Used

Subtractive manufacturing works with many materials. The table below lists the most common ones:

You can pick from metals, plastics, wood, stone, and more with subtractive methods.

Applications

Subtractive manufacturing is used in lots of industries. Here are some examples:

• Car companies use it to test new engine parts fast.

• Medical makers use it for implants and tools.

• Mold makers use it to make molds for other products.

Advantages

Subtractive manufacturing has many good points:

Special machines can make parts as exact as ±0.0025 mm. You can finish many parts fast when you need a lot.

Limitations

There are some things to think about with subtractive manufacturing:

Tip: Some industries, like aerospace, use both subtractive and additive methods together for better results.

Comparison

Process

There is a clear difference in how these methods work. Additive Manufacturing makes things by adding layers. You start with a digital design. The machine puts material only where it is needed. Subtractive manufacturing takes away material from a solid block. CNC machines help cut, drill, or grind off extra parts.

Additive Manufacturing helps you make complex designs fast. You can make small batches or custom items quickly. Subtractive manufacturing needs more setup and programming. It works best for making many parts that are the same. If you want a part with lots of details, Additive Manufacturing is more flexible.

Tip: Additive Manufacturing makes small, complex parts faster. Subtractive manufacturing is better for making lots of simple shapes.

Cost

You should think about cost before picking a method. The table below shows how costs compare:

Additive Manufacturing saves money for a few custom parts. Subtractive manufacturing costs less for big batches or large pieces. You also spend less on electricity and waste with Additive Manufacturing.

Equipment

Each method uses different machines. Additive Manufacturing uses printers like FDM, SLS, and DMLS. Subtractive manufacturing uses CNC mills, lathes, and waterjet cutters. The table below shows average costs:

Entry-level Additive Manufacturing machines cost less than top CNC machines. Both methods need expensive equipment for advanced jobs.

Training

You need training to use these machines safely. Additive Manufacturing operators learn about process checks and material tests. Courses last two or three days. You learn how to prepare for audits and spot risks. Subtractive manufacturing operators train in CNC programming and machine setup. You spend more time learning CNC machines because they have more steps.

Note: Additive Manufacturing training teaches certification and inspection. Subtractive manufacturing training teaches machine use and programming.

Environmental Impact

Choosing the right method helps the environment. Additive Manufacturing uses less energy and makes less waste. Studies show Additive Manufacturing can use up to 25% less energy. It also cuts material waste by up to 90%. You skip many energy-heavy steps found in older methods.

Recent studies show Additive Manufacturing lowers carbon emissions and saves resources. FDM printing has less social impact than CNC machining. Additive Manufacturing also makes lighter airplane parts, which saves fuel and lowers emissions.

Tip: Additive Manufacturing has a much lower carbon footprint. Subtractive manufacturing can leave up to half the material as waste.

Part Size & Complexity

Pick the method that fits your part size and design. Additive Manufacturing works best for small, complex parts. You can make shapes that are hard or impossible with subtractive methods. Subtractive manufacturing is better for big parts. If you want a simple, strong part, subtractive manufacturing gives a smooth finish and high strength.

• Additive Manufacturing lets you make custom shapes and fine details.

• Subtractive manufacturing makes big, strong parts with smooth surfaces.

Material Waste

Additive Manufacturing saves material. It makes 70-90% less waste than subtractive manufacturing. Subtractive manufacturing can leave up to half the block as scrap. You spend less on waste and help the environment with Additive Manufacturing for small, detailed parts.

• Additive Manufacturing: Little waste, uses materials well.

• Subtractive manufacturing: More waste, higher disposal costs.

Choosing a Method

Project Needs

First, think about what your project needs. Decide what material you want to use. Think about how many parts you need. Look at the shape of your design. If you want flat faces or holes, subtractive manufacturing is more exact. If your part has tricky shapes or needs fast changes, additive manufacturing is better.

Here are some important things to think about:

1. What material you will use

2. How many parts you need

3. The shape of your part

4. Your project timeline and changes

You should also think about cost, how long it takes, how hard the part is to make, quality, and what materials you need. For example, small corners need special tools in machining. Additive methods can make tricky shapes without problems.

Industry Use

Different jobs use these ways in their own style. Factories pick additive manufacturing for speed and tough designs. Medical jobs use it for custom parts and new ideas. Space jobs use it for fast testing and special skills.

Additive manufacturing is changing how things are made. You can make custom items and try new ideas faster. Many companies now use this way to make lots of products.

Trends

Now, there are new ways called hybrid manufacturing. This mixes additive and subtractive methods in one machine. Hybrid manufacturing makes things faster and lets you make tricky shapes with good detail.

Hybrid manufacturing uses 3D printing for fast testing. You can change designs quickly without waiting for CNC machines.

For tricky parts, you get design freedom from 3D printing. You also get smooth surfaces from subtractive methods. This makes lighter and more comfy parts.

Hybrid machines help you make parts with tricky shapes, less time, less waste, and lower costs. You can react to changes fast and make special products that are different from others.

You can spot big differences between additive and subtractive manufacturing. Additive is good for making custom and complex parts. It also helps when you need to change things fast. Subtractive is better for making big, simple parts in large numbers. Here is a checklist to help you pick:

Check out groups like the Manufacturing Extension Partnership and Advanced Manufacturing Supply Chain Hub. Factories will soon use smart tools, AI, and new tech. Keep learning so you can change your plans when needed.

FAQ

What is the main difference between additive and subtractive manufacturing?

Additive manufacturing builds parts by stacking layers. Subtractive manufacturing takes away material from a solid block. Additive is better for making tricky shapes. Subtractive is better for strong and simple parts.

Can you combine additive and subtractive methods?

You can use both ways at the same time. Hybrid machines print a part first. Then, they use cutting tools to finish it. This lets you make cool designs and get smooth surfaces.

Which method creates less waste?

Additive manufacturing makes less waste. You only use the material you need for each part. Subtractive manufacturing leaves more extra pieces because you cut away material.

Is additive manufacturing faster than subtractive manufacturing?

Additive manufacturing is faster for making test parts and custom items. Subtractive manufacturing is better when you need lots of the same part. Pick the way that fits your project’s size and speed.