You must be ever attracted by machines’ exquisite craftsmanship, entering a world full of awe, and amazed by the methods and clever art that make them a reality. Everyone has a unique set of qualities, strengths, and weaknesses. But what are their specific differences? Let’s compare precision vs accuracy in machining side by side and identify the differences between them.
Table of Contents
- 1 What Is Precision in Machining?
- 2 What Is Accuracy in Machining?
- 3 Differences Between Precision vs Accuracy in Machining
- 4 4 Main Examples of Typical Precision vs Accuracy in Machining
- 5 Are Precision and Accuracy Important in Machining?
- 6 How to Measure and Inspect Precision vs Accuracy in Machined Parts?
- 7 Methods of Improving the Precision and Accuracy of Machining Process
- 8 Precise and Accurate Parts Used in Different Industries
- 9 Need High Precision and Accurate Machined Parts Or Not?
- 10 Try Contacting Team Rapid Tooling Today!
What Is Precision in Machining?
The term ‘precision’ is generally understood as the closeness between the measured value and the true value. This encompasses the effects of both systematic and accidental errors. Moreover, precision in machining plays a crucial role in ensuring the quality, functionality, and interchangeability of machined parts.
Key aspects of precision in machining:
- Consistency: To produce multiple parts of the same specifications without any changes, consistency becomes essential. This is particularly crucial for mass production and assembly processes demanding precise assembly of parts.
- Tooling and Equipment: Using high-quality tools, machines, and measurement instruments that are well-maintained and calibrated. Additionally, it typically requires advanced CNC (Computer Numerical Control) machine tools and other precision equipment.
What Is Accuracy in Machining?
Accuracy reflects the degree of matching between the manufactured part and the design model, whereas precision indicates the repeatability of consistently creating the part. Consequently, designers aim to manufacture parts that meet or even exceed the expected machining tolerances.
Key aspects of accuracy in machining:
- 1. Understand the variability during the measurement process.
- 2. Identify the sources of measurement system errors.
Differences Between Precision vs Accuracy in Machining
| Key Differences | Details |
| Different Description of Precision vs Accuracy | Precision refers to the degree of conformity between the actual size, shape, and position of the processed parts and the ideal geometric parameters on the design drawings. Therefore, when these values approach each other, the accuracy will increase. Meanwhile, Accuracy usually refers to the degree of closeness between the measured value and the true value, reflecting the accuracy of the measurement results. |
| Types of Error Displayed | Accuracy reflects errors in the manufacturing system or tool, while precision measurements help to indicate errors between manufactured parts. In other words, systematic errors impact accuracy by causing consistent deviation from the true value, while random errors affect precision by causing variability in repeated measurements. |
| Measurement Frequency | The ultimate goal of precision is to ensure that each component consistently meets the specified diameter within strict tolerance ranges. Moreover, by measuring the diameter according to the standard value, we can check its accuracy, which, in turn, will confirm that the component meets the required specifications. |
In short, precision deals with repeatability and consistency, while accuracy deals with correctness relative to standards. Both are crucial in precision vs accuracy mechanical processing, but their evaluation methods are different – evaluating accuracy through multiple measurements and comparing accuracy with standard values.
4 Main Examples of Typical Precision vs Accuracy in Machining
Although precision and accuracy are both very important in mechanical processing, their meanings and focus are different. Accuracy focuses on the consistency between measured values, while precision focuses on the degree of closeness between measured values and true values. In practical applications, both factors need to be considered simultaneously to ensure the quality and efficiency of the manufacturing process:
- Precise and accurate
- Not precise but accurate
- Precise but not accurate
- Not precise and not accurate
Are Precision and Accuracy Important in Machining?
Are precicion and accuracy important in maching? Yes! Function, performance, and assembly during the assembly process are three important aspects of accuracy in manufacturing. Meanwhile, precision is crucial for the consistency of multiple batches of parts.
- Precision machining refers to mechanical parts with high production accuracy and good repeatability. Therefore, precision CNC machining ensures the required standards of accuracy and precision by using various instruments and measurements to ensure the required standards of accuracy and precision.
- If any system errors occur during the manufacturing process, it is necessary to check whether there are defects in the machinery, tools, or precision testing instruments.
- Reducing material waste and improving reliability are crucial goals in manufacturing. By accurately measuring the precision of individual machined parts, potential defects can be identified at an early stage. Consequently, this allows for immediate adjustments to the manufacturing process, thereby enhancing overall efficiency and quality.
- Accurate parts not only improve assembly speed and efficiency but also reduce downtime and labor costs, thereby enhancing the overall efficiency of the production line.
How to Measure and Inspect Precision vs Accuracy in Machined Parts?
Measurement System
Coordinate measuring machines, gauge blocks, calipers, and 3D laser scanning are typically used for dimensional measurement. Meanwhile, roughness testing, Rockwell hardness testing, and non-destructive testing serve as non-dimensional measurement methods.
Measurement System Analysis
Measurement system analysis is a statistical method used to evaluate the variability of the measurement process and determine how much variation in the measurement data is caused by the measurement system itself, as well as how much variation is caused by the measured component or process. The following is a detailed explanation of measurement system analysis:
- Understanding the variability during the measurement process involves analyzing the measurement system; as a result, both systematic and random variations can be effectively evaluated.
- Identifying the sources of measurement system errors: Measurement system analysis can help to identify the sources of errors in measurement data, including systematic errors and random errors.
- It is a technique that uses statistical methods to evaluate the performance of measurement systems. It involves analyzing various errors that may occur during the measurement process to determine the extent to which these errors affect the measurement results.
Here are some analysis approaches of measurement system analysis:
| Approaches | Description |
| Stability | It assesses if data from repeated trials consistently reflect accurate calibration, ensuring long-term measurement accuracy. For instance, stable systems yield consistent results under identical conditions. |
| Bias | It is the difference between average measured values and the true value, indicating systematic errors, such as a thermometer reading consistently higher than actual temperatures, requiring recalibration. |
| Linearity | It evaluates if a measurement device maintains accuracy across its range, ensuring reliability in both light and heavy measurements, as seen in scales that perform accurately across varied weights. |
Measuring in Precision
Repeatability: In precision measurement, repeatability refers to the consistency between the results obtained from multiple consecutive measurements of the same object under identical measurement conditions. Consequently, high repeatability indicates that the measurement process is stable and reliable, thus providing accurate measurement data.
Processing repeatability: Processing repeatability refers to the consistency in size and shape of parts made by different batches or machine tools under identical conditions. It is a key indicator of measurement stability and reliability. By strictly controlling conditions and utilizing appropriate statistical methods, repeatability can be enhanced, thereby ensuring reliable and effective measurement results.
Measuring in Accuracy
Accuracy refers to the degree to which a measured value is close to the true value, while deviation, stability, and linearity are the main influencing factors.
Methods of Improving the Precision and Accuracy of Machining Process
In CNC machining, several factors, including the design phase, machine performance, machining variables, settings, and cutting tools, influence both precision vs accuracy.
| Methods | Pros | Detailed explanation |
| Design for Manufacturability (DFM) | It is an advanced design concept aimed at improving product design quality, reducing production costs, and shortening product time to market. It ensures that the design solution meets both functional requirements and is easy to produce and maintain by considering manufacturing factors during the design phase. | Confirm the capability of the current manufacturing processConduct manufacturability analysisOptimize design and manufacturing processesIntroduce automation technologyUsing high-precision measuring instruments |
| Design meets strict tolerance limits. | Ensuring that the design meets strict tolerance limits is an important aspect of mechanical design, which directly affects the quality and performance of the product. | Clear tolerance requirementsChoose appropriate materials and manufacturing processesOptimize design drawings |
| Optimizing machining and cutting parameters | Improve the efficiency and quality of mechanical processing. | Select cutting parameters based on material typeOptimize using CNC systems and software |
| Implementing effective fixture technology | Improve machining accuracy and efficiency. | Understand the basic concepts of fixturesSelect fixture type based on processing requirementsOptimize fixture designPerform fixture verification and adjustment |
| Motion coupling | This connection method can be mechanical, electrical, or other forms, with the aim of ensuring that each component can maintain precise relative position and motion trajectory during the movement process. | Refers to the synchronous motion between two or more moving objects through a certain connection method. |
Precise and Accurate Parts Used in Different Industries
Precision vs accuracy parts effects in different industries and the following are some specific industry applications:
- Aerospace: In the aerospace sector, precision parts are crucial, as they ensure both the performance and safety of aircraft. Specifically, precision parts such as aircraft engine blades, turbine components, and control system components must undergo meticulous machining and testing. Consequently, this ensures their reliable operation, even under extreme conditions.
- Automobile Manufacturing: Precision parts such as engine components, transmission system components, and braking system components are crucial for ensuring vehicle performance, safety, and reliability.
- Medical Devices: The medical device industry highly demands precision parts. This is because these components are crucial for equipment performance and patient safety.
- Electronics and Semiconductor Industry: Due to the miniaturization and high-performance requirements in smartphones, tablets, and other portable electronic devices, precision machining becomes an indispensable technology. For instance, microprocessors, storage chips, and other electronic components all require precision machining to achieve their functions. Furthermore, these parts need to have high precision and stable electrical performance to meet the rapidly developing demands of electronic technology.
- Energy and Environmental Protection: In energy and environmental protection, precision parts like wind turbine blades, solar panel components, and environmental equipment are vital for boosting energy efficiency and cutting pollution. Thus, these parts must be meticulously designed and processed to ensure stable performance under diverse conditions.
Need High Precision and Accurate Machined Parts Or Not?
The overall precision and accuracy of CNC machining are influenced by multiple factors. Therefore, to enhance these factors and improve machining quality, comprehensive consideration and optimization are essential in the design phase, machine performance, machining variables, settings, and cutting tools. Furthermore, introducing automation technology and utilizing high-precision measuring instruments are also critical methods to boost processing quality and efficiency.
Looking ahead, as technology advances and the industry develops, CNC machining will continuously improve and perfect. Therefore, this will offer more reliable and efficient support for manufacturing growth.
Try Contacting Team Rapid Tooling Today!
TEAM Rapid is a professional manufacturer that offers a series of manufacturing services such as CNC machining, injection molding services, and die casting services to meet customer needs. This detailed guide helps you achieve precision and accuracy in machining simultaneously while identifying their differences, thus enhancing the overall accuracy and consistency of your CNC creations. Our experienced designers and mechanics can handle designs with tolerances as small as millimeters or even smaller. So, please apply for a processing service quotation from our engineers by uploading your drawings. Contact us today!
