Round Broaching: The Complete Guide

In the field of modern mechanical processing, Round broaching, as an efficient and precise processing method, is playing an increasingly important role. Whether in automobile manufacturing, aerospace or other precision processing industries, Round broaching provides a reliable solution for the processing of various Round inner holes with its unique advantages. This guide will take you through a comprehensive understanding of Round broaching, from its principles and tools to applications and advantages, giving you a deeper understanding of this processing technology.

What is Round Broaching?

Round broaching is a machining process that uses a Round broach to enter the Round inner hole from one end of the workpiece under the action of tension, and sequentially removes the metal through multiple cutting teeth on the broach, gradually enlarging the size of the inner hole, and finally obtaining the required accuracy.

What is Round Broaching

The cutting teeth on the broach gradually increase in height, and each cutting tooth removes a certain thickness of metal as it passes through the inner hole. As the broach continues to advance, the size of the inner hole gradually increases until it reaches the design requirements. This processing method can complete the rough machining, semi-finishing and finishing machining of the inner hole at one time, which greatly improves the processing efficiency and accuracy.

The Structure Of The Round Broach

The Structure Of The Round Broach

The round broach usually consists of a shank, a neck, a transition taper, a leading part, a cutting part, a calibration part and a trailing part.

  • Handle: used to install on the broaching machine to transmit pulling force.
  • Neck: connects the shank and transition taper, usually thin, to facilitate the installation and adjustment of the broach.
  • Transition taper: Make the broach gradually transition from the diameter of the shank to the diameter of the cutting part.
  • Leading part: When broaching starts, it guides the broach into the inner hole of the workpiece to ensure the accuracy of broaching.
  • Cutting part: Contains multiple cutting teeth and is the main part of the broach for cutting.
  • Calibration department: Calibrate the processed inner hole to improve the dimensional accuracy and shape accuracy of the inner hole.
  • Rear guide part: At the end of broaching, it guides the broach out of the inner hole of the workpiece to prevent the broach from scratching the surface of the inner hole.

6 Steps Processing Of Round Broaching

Step1: Workpiece Preparation

First, select the appropriate workpiece material and size according to the processing requirements. Then, perform necessary pretreatment on the workpiece, such as removing burrs, cleaning the surface, etc.

Step2: Broach Selection

According to the diameter, depth and accuracy requirements of the inner hole of the workpiece, select a round broach of appropriate specifications. At the same time, factors such as the broach material and cutting parameters should be considered.

Step3: Installation And Debugging

Install the round broach on the broaching machine and perform debugging to ensure the position accuracy of the broach and the sharpness of the cutting edge. At the same time, the parameters such as the pulling force and feed speed of the broaching machine are adjusted to adapt to different processing requirements.

Step4: Broaching

Start the broaching machine, the broach enters the inner hole of the workpiece under the action of tension, and broaching begins. During the processing, the processing status, such as cutting force, temperature, sound, etc., should be closely observed. If there are any abnormalities, the machine should be stopped for inspection in time.

Step5: Quality Inspection

After the broaching process is completed, the inner hole of the workpiece is inspected for quality, including dimensional accuracy, shape accuracy, surface roughness, etc. If it does not meet the requirements, appropriate adjustments or repairs should be made.

Advantages Of Round Broaching

High-precision Machining

Round broaching can produce very precise Round inner holes, with high dimensional accuracy and shape accuracy. This is of great significance to some industries that require extremely high precision, such as aerospace and precision instrument manufacturing.

High Efficiency Production

Multiple machining processes for the inner hole can be completed in one broaching operation, greatly improving production efficiency. Compared with traditional processing methods, Round broaching can save a lot of processing time and labor costs.

Good Surface Quality

The cutting process of the round broach is smooth and can obtain lower surface roughness and improve the surface quality of the inner hole. This is very important for some inner hole processing that requires good sealing performance or fitting accuracy.

Adaptable

Workpieces of various materials can be processed, including steel, cast iron, aluminum alloy, copper, etc. At the same time, there are round broaches of corresponding specifications available for Round inner holes of different diameters and depths, which are very adaptable.

Application Of Round Broaching

Automobile Manufacturing

In the production of automobile engines, transmissions and other components, Round broaching is widely used to process various Round inner holes, such as cylinder bores, crankshaft holes, gear inner holes, etc. These inner holes require high precision, and Round broaching meets the demands of the automotive manufacturing industry for high-quality parts.

Aerospace

The aerospace industry has extremely high requirements on precision and quality of components. Round broaching can process key parts such as the mounting holes of aircraft engine blades and the cooling holes of turbine disks to ensure the performance and reliability of parts.

Machining

In various machining industries, Round broaching is also widely used to process Round inner holes such as bearing holes, sleeve holes, and hydraulic valve holes. These inner holes often require high-precision machining, and Round broaching is an ideal machining method.

How To Right Choose Round Broach?

To correctly choose a round broach, you can consider the following aspects:

Clarify Processing Requirements

1.Workpiece material

  • Different materials have different hardness, strength and processing properties. For example, steel, cast iron, aluminum alloy and other materials have different requirements for round broaches. For materials with higher hardness, you need to choose round broaches with higher hardness and better wear resistance, such as carbide round broaches; for softer materials, you can choose high-speed steel round broaches.
  • Understand the cutting performance of the material, such as whether it is easy to produce built-up edge, whether it is easy to stick to the tool, etc., in order to choose the appropriate tool coating and cutting parameters.

2.Bore size and shape

  • Accurately measure the diameter, depth and shape accuracy requirements of the inner hole of the workpiece. Select a round broach of appropriate specifications according to the inner hole size to ensure that the diameter and length of the broach can meet the processing needs.
  • If the shape of the inner hole is complex, such as with steps, chamfers, etc., you need to choose a specially designed round broach, or consider using a combination of multiple broaches for processing.

3.Processing accuracy requirements

  • Determine the dimensional accuracy, shape accuracy and surface roughness requirements of the inner hole. For high-precision machining requirements, it is necessary to choose a round broach with high manufacturing precision and sharp cutting edge. At the same time, the design of the calibration part of the broach should be considered to ensure the accuracy of the inner hole after processing.
  • If the processing requirements are very strict, you can consider using imported high-end round broaches or customized special round broaches.

Consider The Performance Parameters Of Round Broaches

1.Tool material

  • High-speed steel: has good toughness and processability, and is relatively cheap. Suitable for processing with general precision requirements.
  • Carbide: high hardness, good wear resistance, able to withstand high cutting temperatures and cutting forces. Suitable for processing materials with higher hardness and processing with high precision requirements.
  • Coating materials: Coatings such as TiN and TiAlN can improve the wear resistance, heat resistance and cutting performance of the tool. Select the appropriate coating material based on processing needs.

2.Cutting parameters

  • Cutting speed: Determine the appropriate cutting speed based on the tool material and workpiece material. Too high a cutting speed may cause the tool to wear too fast, and a too low cutting speed will reduce the processing efficiency.
  • Feed amount: The feed amount directly affects the processing efficiency and surface quality. Choose the appropriate feed amount based on machining accuracy requirements and tool life.
  • Cutting depth: A reasonable cutting depth can improve processing efficiency, but an excessive cutting depth may cause tool damage. Determine the appropriate depth of cut based on the workpiece material and tool performance.

3.Tool life

  • Understand the life expectancy of a round broach and consider the tool’s durability and resharpenability. Some high-end round broaching tools have a long service life, which can reduce the number of tool changes and improve production efficiency.
  • At the same time, the maintenance and upkeep costs of the tool should be considered and a cost-effective round broach should be selected.

Choose Reliable Suppliers

1.Brand and Reputation

  • Choose a well-known brand of round broach supplier, these brands usually have high quality assurance and good after-sales service. You can understand the supplier’s reputation by reviewing industry reviews, customer feedback, etc.
  • Consider the supplier’s history and experience and choose a supplier with extensive experience and expertise that can better meet your processing needs.

2.Technical support and after-sales service

  • Whether the supplier can provide technical support, such as tool selection suggestions, processing parameter optimization, etc. During the processing, if problems are encountered, can the supplier provide timely solutions?
  • Understand the supplier’s after-sales service policy, including tool repair, replacement and returns. Ensure that you can receive timely support and protection during use.

3.Price and value for money

  • Compare the prices of round broaches from different suppliers, but don’t make your selection solely based on price. It is necessary to comprehensively consider factors such as the quality, performance and after-sales service of the tool, and choose a cost-effective round broach.
  • Can negotiate with suppliers for better prices and preferential terms.

To sum up, the correct choice of round broaches requires comprehensive consideration of processing requirements, tool performance parameters, suppliers and other factors. Through careful analysis and comparison, choosing a round broach that suits your processing needs can improve processing efficiency, ensure processing quality, and reduce production costs.

How To Judge The Quality Of Round Broaches?

To judge the quality of round broaches, you can consider the following aspects:

Step1: Appearance inspection

1.Surface quality

  • The surface of a high-quality round broach should be smooth and flat, without obvious scratches, cracks, rust spots and other defects. The roughness of the tool surface is low, indicating high machining accuracy.
  • Check whether the coating of the tool is uniform, complete and free of peeling. Coatings can improve a tool’s wear resistance, heat resistance and cutting performance.

2.Dimensional accuracy

  • Use measuring tools to measure the diameter, length, cutting tooth height and other dimensions of the round broach to check whether it meets the design requirements. Tools with high dimensional accuracy can ensure the accuracy of the machined inner hole size.
  • Pay attention to check whether the shank size of the tool matches the chuck of the broaching machine to ensure a secure installation.

Step2: Material And Hardness

1.Material analysis

  • Understand the materials used in round broaches. Common ones include high-speed steel, carbide, etc. Different materials have different performance characteristics and are suitable for different processing needs.
  • High-speed steel has good toughness and machinability, and its price is relatively low; cemented carbide has high hardness and good wear resistance, and is suitable for processing materials with higher hardness.

2.Hardness test

  • A hardness tester can be used to test the hardness of round broaches. Hardness is one of the important indicators to measure the wear resistance and cutting performance of cutting tools.
  • Generally speaking, the higher the hardness, the better the wear resistance of the tool, but the toughness may be reduced accordingly. It is necessary to select a tool with appropriate hardness according to specific processing needs.

Step3: Cutting Edge Quality

1.Edge sharpness

  • Observe whether the cutting edge of the round broach is sharp. Sharp cutting edges can reduce cutting forces and improve processing efficiency and surface quality.
  • You can use a magnifying glass or microscope to check the microstructure of the cutting edge to see if there are defects such as chipping or saw teeth.

2.Cutting tooth shape

  • Check whether the shape of the cutting teeth of the round broach is regular and consistent. The height, angle and other parameters of the cutting teeth should meet the design requirements to ensure the stability and processing accuracy of the cutting process.
  • Pay attention to whether the rake angle, relief angle and other parameters of the cutting teeth are reasonable. These parameters will affect the cutting performance and life of the tool.

Step4: Processing performance test

1.Trial cutting

  • Carry out trial cutting under actual processing conditions to observe the processing effect of the round broach. It mainly includes the dimensional accuracy, shape accuracy and surface roughness of the inner hole after processing.
  • Pay attention to the cutting force, temperature, sound, etc. during the cutting process to determine whether the tool is stable and reliable.

2.Tool life

  • Evaluate the life of the round broach through multiple trial cutting or actual production applications. Round broaches with long tool life can reduce production costs and improve production efficiency.
  • Record the wear of cutting tools and analyze the causes of wear in order to further improve the design and use of cutting tools.

Step5: Brand and manufacturer reputation

1.Brand awareness

  • Choose a round broach from a well-known brand, and the quality is usually more guaranteed. Manufacturers of well-known brands invest heavily in the design, manufacturing, and quality control of cutting tools, and their product quality is relatively stable.

2.Manufacturer reputation

  • Understand the manufacturer’s production scale, technical strength, after-sales service, etc. Reputable manufacturers can provide high-quality products and timely technical support.
  • You can understand the reputation of the manufacturer by checking the manufacturer’s qualification certificate, customer reviews, industry reputation, etc.

To sum up, judging the quality of round broaches requires comprehensive consideration of appearance, material, cutting edge quality, processing performance, brand and manufacturer reputation, etc. When choosing a round broach, you should choose a tool with reliable quality and excellent performance based on your specific processing needs and budget.

Conclusion

As an efficient and precise processing method, Round broaching plays an important role in the field of modern mechanical processing. Through the introduction of this guide, I believe you have a more comprehensive understanding of Round broaching. In practical applications, it is necessary to select appropriate Round broaching tools and processing parameters according to processing requirements, strictly abide by operating procedures, and pay attention to tool maintenance and safe operation, so as to give full play to the advantages of Round broaching and provide reliable processing for high-quality parts. Assure.

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