Boring Machining: A Detailed Guide
Precision machining is the backbone of the manufacturing industry.
It has various machining processes– among which boring machining also plays a vital role. It is a machining process that caters to multiple applications.
If you are inclined to learn more about boring machining, you can read the guide below.
What is Boring Machining?
Boring machining is a precise process that enlarges the holes that are already drilled in components.
The main purpose of considering machining is to make the holes meet the specific requirements of surface finishing and dimensions.
It consists of a tool that rotates and widens the hole, making it highly accurate and smooth.
Boring machining was invented in the 18th century by John Wilkinson, who invented it in 1774 to manufacture blocks in cylindrical shapes for steam engines.
As time passed on, advancements followed in 1860; Francis A Pratt’s machine was innovated, which used a screw feed manually.
Even during the world wars, jig borers were invented, and in the 1970s, CNC machines were all over, taking the place of mechanical systems. The boring machine was then controlled by a computer.
The Advantages of Boring Machining
The boring machining process has a wide range of advantages, and some of these are as follows:
- Boring machining is a highly accurate process and helps to create holes in different materials that are not achievable by drilling.
- This process even helps to achieve the finest surface finishing, which can create a surface finish that is up to 32 micro inches.
- Boring machining is a versatile process, and it is compatible with a wide range of materials, such as aluminum, steel, plastic, and wood. It can enlarge not only round holes but also keyways, slots, and grooves.
- Boring machining gives you an opportunity to create holes of customized sizes and is crucial in applications that require high precision.
- The automated boring machines are quick, and hence, the time needed to create the enlargements in holes is less, which makes them efficient. Hence, it proves to be suitable for high-volume applications.
The Disadvantages of Boring Machining
Boring machining also has some downsides which cannot be ignored, and these are as follows:
- The cost of equipment is high, and it cannot be justifiable for a small business or a project that has a small volume.
- Boring machining requires skills for operation; hence, to achieve efficiency and accuracy, you must invest in labor training.
- It can only enlarge the holes that already exist and cannot drill fresh holes.
- When the hole is too deep, the risk of tool deflection is present, especially when the boring bar lacks rigidity.
How Does Boring Machining Work?
The working mechanism of boring machining is given as follows:
- The process uses a CNC milling machine or a lathe and a tool called a boring bar, which is fixed with a cutting insert.
- A hole is first made by drilling.
- In the pre-drilled hole, the boring bar is inserted, and the lathe rotates the workpiece. At the same time, the boring tool is stationary and trims the inner edges of the hole. The hole is then enlarged.
- The process continues unless the required surface finish and dimensions are achieved.
Types of Boring Machines
There are different types of boring machines, and these are as follows:
Vertical Boring Machines
A vertical boring machine carries out the boring task in a vertical direction.
The workpiece on which the boring has to take place is placed on a rotary table, and the boring tool cuts from top to bottom. Vertical boring machines are suitable for heavy and large components.
Horizontal Boring Machines
A horizontal boring machine is designed to bore holes horizontally. It has a spindle aligned horizontally and holds the boring tool. This machine is suitable for larger components that require precise boring.
Precision Boring Machines
Precision boring machines are meant specifically for boring and have a size smaller than milling machines and lathes. They are highly suitable for small components and offer excellent surface finishing.
Table Type Boring Machines
A table-type boring machining tool can bore holes in the horizontal direction, but it is small and mounted on a table.
Floor Boring Machines
Floor boring machine is a large machine that can bore massive components. The component is placed on the floors, and the boring tool is fixed on the moveable column.
It is very commonly used in heavy duty industries like manufacturing larger equipment and shipbuilding.
Applications of Boring Machining
The boring machining process offers to manufacture components for multiple industries, and some of these are discussed below:
Automobile
In the automobile industry, boring machining creates bores in engine blocks and cylinders which helps to enhance the efficiency and performance of engines.
Aerospace
The aerospace industry uses the process of boring machines for its components, like landing gears and turbine casings, with accurate dimensions.
Construction
The construction industry requires creating large holes in concrete to cater to infrastructure projects, and hence, boring machining is widely opted for.
Oil and Gas
Components in the oil and gas industry, like pump housing and valve bodies, need exact dimensions to be bored, and the oil and gas industry caters to them.
Challenges for Boring Machining
Boring machining is a challenging process, and some of the challenges encountered in this process are as follows:
- When the process of boring is done, the presence of friction may result in wear and tear or tool, which impacts the performance of the machine.
- Machining errors experienced while boring machining may alter the dimensions, location, and surface finish of the holes.
- Sometimes, the components after boring machining may have a lack of surface finishes like lines on the components, which is due to the incorrect feed rate.
- Measurement error is a major challenge in boring machining. If inappropriate tools are used or incorrect measurements are entered, the results are not accurate.
Practical Tips for Boring Machining
Boring machining processes can enhance the optimal results if the following tips are considered during the process:
- Keep a check on the tool wear, replace the damaged cutters, and ensure that the clamps hold the tool tightly during the machining process.
- Ensure that coolants are used during boring machining so that heat can be managed, and it even helps reduce friction.
- Measure the diameter of the hole using a caliper and, based on that, calculate the machining allowance.
- Keep an allowance of 0.3 to 0.5 on the boring tool, and for roughness, make sure that the allowance is not less than 0.5mm.
Boring vs. Other Machining Methods
There are various processes that can be considered to compare with the boring machining process, and these are as follows:
Boring vs. Drilling
Boring and drilling are both processes that remove material. Drilling, however, creates a hole in the workpiece, but boring improves the hole by enlarging it.
Drilling doesn't offer the surface finish that is offered by boring. The holes created by drill are narrow, whereas the ones created by boring are wide.
Boring vs. Turning
Turning is also a process that removes material from the workpiece. Boring has a single tool for cutting, which has a pointed head, whereas turning has a cutting tool that does not rotate and removes external materials.
The main difference between both is that turning works on the external surface, whereas boring works on the internal surface.
Boring vs. Reaming
Reaming and boring are both cutting processes and removing the material from the internal part of the component.
However, the process of boring consists of a tool that has a single pointed head, and the reaming uses cutters that rotate and cut the material.
They both work on holes that are pre-drilled. The main difference lies in the application process; boring broadens the hole and creates a smooth internal wall.
Conclusion
Boring machining is used for a lot of applications and components, as you must have understood in the guide above.
If you are seeking a reliable service partner that offers you high-quality components with bored holes, you can get in touch with DEK. We have specialized machinery and trained labor for boring machining services.
FAQs
What is the purpose of boring?
The main purpose of boring is to enlarge pre-drilled holes and improve their surface finish.
What are examples of boring tools?
There are different types of boring tools, such as starter drills, boring bars, and boring drills.
What types of materials can be effectively machined using boring machining?
The process of machining is highly versatile and can be chosen for materials which include metals, plastics, and even wood.
