In the field of machinery manufacturing, milling is the core process that supports the development of many industries (such as automotive, aerospace, precision electronics), and milling manufacturers manufacturer) product quality directly determines the product performance and safety of downstream industries. For practitioners who need to source milling products or focus on manufacturing, understanding how milling manufacturers ensure quality is key to screening partners and managing supply chain risks. This article will dismantle the quality assurance path of milling manufacturers in detail from the core dimensions of quality control system, raw material management, and production process monitoring, combined with actual cases and professional methods.
1. Introduction
1.1 Introduce the importance of milling manufacturing
As an important branch of metal cutting processing, milling manufacturing can complete the processing of various complex structures such as planes, grooves, and gears through the rotational movement of the milling cutter and the feed motion of the workpiece. According to industry data, about 60% of the world's precision mechanical parts need to go through milling and processing; In the aerospace field, the milling accuracy of core components (such as engine blade mounts) directly affects flight safety, and its machining pass rate is as high as 99.9%. Whether it is high-end equipment manufacturing or daily industrial product production, milling manufacturing plays a "cornerstone" role, and the processing capacity and quality level of milling manufacturers are the core support for industrial upgrading.
1.2 The Critical Role of Quality in Milling Manufacturing
Quality is the core competitiveness of milling manufacturers, and it is also the primary criterion for downstream customers to choose partners. Taking the auto parts industry as an example, a well-known car company once had a size deviation of 0.02mm due to the size deviation of the milling gearbox gear purchased by a large number of vehicles, resulting in a shifting problem of batch vehicles, and the final recall loss exceeded 200 million yuan, and the milling manufacturer involved also lost the core cooperation qualification. On the contrary, milling manufacturers with stable quality can not only obtain long-term stable orders, but also enter the high-end market by virtue of word of mouth. For milling manufacturing, quality not only means that dimensional accuracy, surface roughness and other indicators are up to standard, but also covers product consistency, stability and service life, which is directly related to the safety and efficiency of the entire supply chain.
2. Quality control system
2.1 Quality management standards (e.g. ISO 9001)
Mainstream milling manufacturers build their quality systems based on authoritative quality management standards, with ISO 9001 being the core general standard. The standard requires manufacturers to establish a full-process quality control mechanism from customer demand identification, production planning to product delivery, emphasizing "continuous improvement" and "customer satisfaction". For example, after a large domestic milling manufacturer (serving the new energy vehicle industry) passed the ISO 9001:2015 certification, the standard requirements were refined into 12 core process documents, among which the CPK value (process capability index) of key processes was clearly required to ≥be 1.33 for the "process capability confirmation" link of milling processing, so as to ensure the stability of mass production. In addition, for high-end fields, some milling manufacturers will also pass special standards such as ISO 13485 (medical field) and AS9100 (aerospace field) to further strengthen the professionalism of quality control.
2.2 Establishment of quality control process
Perfect quality control process is the core starting point to ensure quality, mature milling manufacturers will establish a whole process mechanism of "pre-prevention-in-process control-post-improvement", the specific process is as follows:
- Pre-emptive prevention: After receiving the order, organize the technical, quality, and production teams to carry out process review, clarify the key quality characteristics of milling (such as dimensional tolerance, surface finish), and formulate detailed process documents and quality inspection plans.
- In-process control: multiple inspection nodes are set up in the production process, including first article inspection (confirm that the first product is qualified before mass production), inspection (random inspection of 5 products every 2 hours), and final inspection (review product quality after the batch is over);
- Post-event improvement: classify and count non-conforming products (such as dimensional deviations, surface defects), analyze root causes (personnel operation, equipment accuracy, material problems, etc.) through fishbone diagrams, formulate corrective and preventive measures, and track the verification effect.
2.3 Quality audit and evaluation mechanism
Quality audit is a key link to verify the effectiveness of the quality system, and milling manufacturers usually use the three-dimensional evaluation mechanism of "internal audit + external audit + customer audit". Internal audits are carried out quarterly, and full-time quality auditors conduct comprehensive verification of production processes, document records, and inspection data. External audits are conducted annually by certification bodies to verify compliance with standards such as ISO 9001; Customer audits are carried out according to customer needs, focusing on verifying order-related quality control links. For example, a milling manufacturer focusing on precision electronic parts linked the audit results to the performance of the department, and required rectification within 24 hours to ensure the continuous and effective operation of the quality system for problems such as "incomplete inspection records" and "deviation of process parameters" found in the audit.
3. Selection and inspection of raw materials
3.1 Source and supplier management of raw materials
Raw materials are the basis that affects the quality of milling products, and high-quality milling manufacturers will establish a strict supplier access and management system. First of all, in terms of supplier selection, priority will be given to raw material suppliers with ISO 9001 certification, stable production capacity and quality traceability capabilities, and raw material certificates (such as stainless steel composition analysis reports) and quality inspection reports will be required. Secondly, establish a supplier classification mechanism, according to the cooperation period, quality qualification rate, delivery timeliness and other indicators, the suppliers are divided into three levels: A, B and C. Practical data from a milling manufacturer shows that through strict supplier management, its raw material failure rate has decreased from 3.2% to 0.8%, significantly improving the quality of the final product.
3.2 Material inspection standards and testing methods
Before raw materials enter the warehouse, they must go through strict inspection, milling manufacturers usually adopt the dual standard of "appearance inspection + physical and chemical inspection", the specific test methods and inspection items are shown in the table below:
| Inspection category | Inspection items | Test methodology | Eligibility criteria |
|---|---|---|---|
| Appearance inspection | Surface defects, dimensional deviations | Visual inspection, caliper measurement | No cracks, no scale; Dimensional deviation ≤± 0.1mm |
| Physical and chemical testing | chemical composition, hardness | Spectral analysis, Rockwell hardness test | Meet the material grade standards; Hardness ≥ 20HRC |
3.3 The impact of raw materials on the quality of the final product
The quality of raw materials directly determines the processing performance and final quality of milled products. For example, if steel with too high carbon content is used for milling processing, it is easy to have problems such as fast tool wear and burrs on the product surface; If the raw material has internal loosening defects, the product may have stress concentration after processing and break in subsequent use. A milling case in the aerospace field shows that a batch of aluminum alloy raw materials did not reach the design life (only 60% of the standard) in the fatigue test due to excessive impurity content, and finally the whole batch of products was scrapped, causing direct economic losses of more than 5 million yuan. Therefore, the strict control of raw materials by milling manufacturers is a key prerequisite for avoiding subsequent quality risks.
4. Quality control in the production process
4.1 Maintenance and calibration of production equipment
The precision of milling equipment is the core of ensuring the quality of machining, and high-quality milling manufacturers will establish a complete equipment maintenance and calibration system. On the one hand, formulate a daily spot inspection and regular maintenance system for equipment, for example, the CNC milling machine needs to check the lubricating oil level and spindle speed stability before starting the machine every day, clean and lubricate the guide rail once a week, and carry out a comprehensive overhaul once a year; On the other hand, the equipment accuracy is calibrated regularly, and the laser interferometer is used to detect the positioning accuracy and repeated positioning accuracy of the machine tool to ensure that the equipment accuracy meets the processing requirements (such as the positioning accuracy error of precision milling equipment ≤ 0.005mm). Through the operation of this system, a milling manufacturer reduced the proportion of quality problems caused by equipment failures from 15% to 3%, effectively improving production stability.
4.2 Real-time monitoring technology in the production process
With the development of intelligent manufacturing, more and more milling manufacturers are introducing real-time monitoring technology to achieve precise control of the production process. Common monitoring technologies include: tool wear monitoring (detecting tool vibration frequency and cutting force through sensors, judging tool wear status, and avoiding machining deviations caused by tool wear), real-time detection of machining size (using an online measuring instrument to measure the product size in real time, if it exceeds the tolerance range, the equipment will automatically stop and alarm), cutting temperature monitoring (monitoring the temperature of the cutting area through an infrared thermometer to avoid material deformation caused by high temperature). For example, after a precision milling manufacturer introduced an intelligent monitoring system, the size qualification rate of batch processed products increased from 98.5% to 99.8%, while reducing the generation of non-conforming products.
4.3 Optimization and adjustment of process parameters
The rationality of milling process parameters (such as spindle speed, feed speed, cutting depth) directly affects product quality and processing efficiency. Mature milling manufacturers optimize process parameters through experiments and establish a database of process parameters according to different materials and processing types. For example, when processing No. 45 steel, the spindle speed is set to 1200r/min, the feed speed is 150mm/min, and the cutting depth is 2mm, which can improve the processing efficiency while ensuring the machining accuracy; If processing aluminum alloy, it is necessary to appropriately increase the spindle speed (more than 2000r/min) and reduce the cutting depth to avoid the problem of sticking tools. In addition, during the production process, technicians will adjust the process parameters in time based on real-time monitoring data and first article inspection results to ensure the quality stability of mass production.
5. Conclusion
Quality assurance for milling manufacturers is a systematic project that runs through the entire process from quality system construction, raw material control to production process monitoring. By following authoritative standards such as ISO 9001 to establish a complete quality control system, strictly screen and inspect raw materials, strengthen equipment maintenance and real-time monitoring, and optimize process parameters, we can continue to output high-quality milling products consistently and stably. For downstream customers, understanding these quality assurance measures can help them screen partners more accurately; For milling manufacturers, continuously improving quality control capabilities is a key path to enhance core competitiveness and expand the high-end market.
【Yigu Technology's Perspective】As an enterprise deeply involved in the field of milling manufacturing, we believe that quality is the foundation of the survival of milling manufacturers. In the context of the current high-end manufacturing upgrade, traditional quality control methods alone can no longer meet the market's demand for precise and stable products. Milling manufacturers need to actively integrate intelligent monitoring technology, strengthen the digital traceability of the whole process, and deepen collaboration with high-quality suppliers to ensure quality from the source. In the future, the refinement and intelligence of quality control will become the core competition point of the milling and manufacturing industry, and only by continuously iterating the quality system can we achieve long-term development.
FAQ
Q1: What is the core significance of choosing ISO 9001 certification for milling manufacturers? A1: ISO 9001 certification provides milling manufacturers with a general framework for whole-process quality control, with the core significance of standardizing all aspects of operation from order receipt, production and processing to product delivery, ensuring the consistency and stability of product quality, and enhancing customer trust in the enterprise, laying the foundation for entering the mid-to-high-end market.
Q2: What is the core role of physical and chemical inspection in raw material inspection? A2: Physical and chemical inspection can accurately judge whether the chemical composition and mechanical properties of raw materials meet the processing requirements, avoid processing defects caused by problems such as excessive impurities and inconsistent hardness of raw materials, and reduce the quality risk of the final product from the source, especially suitable for milling processing in high-end fields such as aerospace and medical care.
Q3: What is the key value of real-time monitoring technology in improving the quality of milling manufacturing? A3: Real-time monitoring technology can realize the dynamic control of the production process, timely detect tool wear, dimensional deviations, temperature abnormalities and other problems and trigger early warnings, avoid the generation of batch non-conforming products, reduce the error of manual inspection, and improve the accuracy and efficiency of quality control.
Q4: How is the calibration cycle determined for milling manufacturers' equipment? A4: The calibration cycle of the equipment needs to be determined based on the equipment type, frequency of use and processing accuracy requirements. Ordinary milling equipment is usually calibrated every six months, and precision milling equipment (such as machining accuracy ≤0.005mm) needs to be calibrated every 3 months. In addition, if the equipment fails and is repaired, it needs to be recalibrated immediately to ensure that the accuracy meets the standard.
