Guide to Shop Custom CNC Machining Services in F&Q TECH

     In April 2025, Apple CEO Tim Cook said in an interview: "The core reason why Apple insists on manufacturing in China is not cheap labor, but China's irreplaceable 'skill density'." This view not only reveals the underlying logic of Apple's supply chain, but also reflects China's global competitiveness in the field of precision manufacturing. This article will deeply analyze how China has become the preferred partner for CNC processing and mold injection services for European and American companies by relying on its technical talent reserves, supply chain efficiency and innovation ecology.

 1.1 “Skill Density” in Cook’s Eyes

     Cook has repeatedly stressed that the core advantage of China's manufacturing industry lies in its large-scale and systematic talent pool. For example, the number of mold engineers in a certain province in China can "fill several football fields", while the United States "can't even gather enough engineers for a meeting." This gap stems from:

Education system support: China's vocational education system focuses on training technical workers, covering high-skilled fields such as CNC programming and mold design.

Industry chain collaboration: From raw materials (such as aluminum alloys and engineering plastics) to precision processing, China has formed a "one-hour industrial circle" to achieve rapid response and cost optimization.

 1.2 The “micrometer-level” threshold for precision manufacturing

     Apple products require mold precision up to micron level (such as the surface fit of iPhone shell), which relies on the following technological breakthroughs:

Popularization of 5-axis CNC machining: China's leading factories have widely used 5-axis linkage machine tools, which can process complex curved parts with an accuracy of ±0.01mm.

Injection molding process innovation: For example, the glass panel produced by Lens Technology for Apple Vision Pro uses high-precision hot bending technology, with a yield rate of over 99%.

Dimensions

Comprehensive cost

Delivery cycle

Technical adaptability

Chinese Manufacturers

Labor + equipment depreciation costs are 30%-50% lower

Average 2-4 weeks (relying on clustered supply chain)

Support flexible production from prototype to mass production

European and American local suppliers

High labor cost, suitable for small batch customization

Prefer standardized large-volume orders

Complex parts take 6-8 weeks

    CNC (Computer Numerical Control) machining is a process that uses programmed machine tools to manufacture high-precision parts. It is widely used in the automotive, aerospace, medical equipment and other fields. Its cost is determined by multiple factors, including design complexity, material selection, and mass production.

Material cost

Material type: Metals (such as aluminum, stainless steel, and titanium alloys) are more expensive than plastics and have different processing difficulties. For example, aluminum is the first choice due to its easy processing and low cost, while titanium alloys are twice as expensive due to their high hardness and low thermal conductivity.

Material machinability: Difficult-to-process materials (such as stainless steel and titanium) require longer time and special tools, which increases costs.

Design and complexity

Geometric complexity: Complex designs (such as deep cavities, thin walls, and sharp corners) require multiple clamping and special tools, which prolongs the processing time.

Tolerance requirements: Standard tolerances (metal ±0.1mm, plastic ±0.25mm) do not require additional fees, but tolerances of ±0.005mm require precision grinding, which increases the cost by 40-200 yuan/hour.

Surface treatment: Sandblasting, polishing, anodizing and other processes are charged on demand. For example, polishing requires manual grinding, and the cost is twice that of the original surface.

Processing time and equipment

Working hours: CNC machine tools are usually charged by the minute, about 80-120 yuan/minute, and five-axis machine tools are more expensive.

Equipment type: Three-axis machine tools are low-cost, and five-axis machine tools are suitable for complex parts but the cost is doubled.

Batch and order size

Batch effect: Single-piece processing requires sharing the initial programming and clamping costs, and batch production can reduce unit costs. For example, the unit price of 1,000 pieces may be 88% lower than that of a single piece.

Additional costs

Urgent orders: The expedited cost is twice the standard price.

Special tools and processes: such as EDM or Wire Cutting, an additional 100-200 yuan per hour.

Material cost estimation

Calculate the amount of raw materials based on the part volume and material density, combined with the market unit price (such as aluminum is about 30 yuan/kg, stainless steel is about 50 yuan/kg).

Processing time calculation

Formula: Total cost = material cost + (processing time × labor unit price) + surface treatment fee.

Example: The material cost of an aluminum alloy part is 100 yuan, the processing time is 30 minutes (unit price 100 yuan/minute), and the total cost is about 3,100 yuan.

Empirical ratio method

Large parts: The ratio of processing fee to material cost is about 1:1 (simple design) or 1.2-1.5:1 (complex design).

Small and medium parts: The ratio is 2-3:1 (simple) or 5-10:1 (complex).

Whenever a CNC machine produces a new product, engineers are required to debug the machine according to the product. Taking the turning machine debugging in the video as an example, excluding the programming time, it takes at least 4 hours to debug the machine.

Optimize design

Avoid thin walls (metal ≥ 0.8mm, plastic ≥ 1.5mm), deep cavities (depth ≤ 4 times the slot width) and inner sharp corners, and use rounded corner transitions instead.

Simplify the number of clamping times and reduce the need for flipping processing.

Rational material selection

Prioritize easy-to-process materials (such as aluminum 6061) and avoid high-cost materials such as titanium alloy unless performance is required.

Standardized process

Use standard apertures and threads to avoid customized tool costs.

Mass production

Expand orders after small-scale trial production to spread the initial costs.

Simple parts: aluminum alloy housing (100×50×20mm), material cost 80 yuan, processing time 20 minutes, total cost about 2080 yuan.

Complex parts: stainless steel precision gear (tolerance ±0.02mm), material cost 200 yuan, processing time 60 minutes, additional polishing cost 500 yuan, total cost about 8300 yuan.

CNC machining costs are affected by many factors such as materials, design, and batch size. Costs can be significantly reduced through optimized design and reasonable planning. It is recommended to communicate with the processing plant about the feasibility of the design at the beginning of the project, and use online quotation tools (such as Mohou.com and Xometry) to quickly estimate the cost.

In the world of CNC machining, the choice of metal materials directly affects machining efficiency, part accuracy and final cost. Although no metal can "take all" in all machining scenarios, some metals have become the "darlings" of CNC machining due to their excellent comprehensive performance. They are not only adaptable to a variety of machining processes, but also can show stable performance in the fields of auto parts, aerospace, etc.

▶ Aluminum alloy is one of the ideal materials for CNC machining, especially in the fields of auto parts and aerospace.

In terms of processing performance, aluminum alloy has moderate hardness (the hardness of common 6061 aluminum alloy is about 95HB), low cutting resistance, slow tool wear, and can greatly improve processing efficiency. Its thermal conductivity is excellent, about 3 times that of steel, and the heat generated during processing can be quickly dissipated to avoid the accuracy of parts affected by thermal deformation. In addition, aluminum alloy has good plasticity, and smooth surface quality can be obtained whether it is milling, turning or drilling, without complicated subsequent processing.

In terms of cost, the price of aluminum alloy raw materials is relatively affordable, and the material utilization rate is high during processing, which is suitable for mass production. For example, engine brackets in the auto parts field and lightweight structural parts in aerospace are mostly processed with aluminum alloys, which can meet strength requirements and achieve weight reduction goals.

▶ Brass has become a popular choice for precision parts processing due to its excellent cutting performance.

Brass has a low hardness (about 50-100HB) and a uniform internal structure. It is not easy to produce burrs and cracks during processing, and can easily achieve high-precision dimensional control (tolerance can be stabilized within ±0.01mm). It has good self-lubrication, is not easy to stick to the tool during cutting, and can reduce tool loss. It is especially suitable for processing parts with fine threads and complex holes, such as hydraulic valve components in auto parts and connectors in precision instruments.

In addition, brass has good conductivity and corrosion resistance. After processing, it can meet the needs of some scenarios without additional plating, further reducing production costs. However, brass has a high density and is relatively limited in its application in weight-sensitive aerospace parts.

Compared to brass, copper is widely used in new energy vehicle charging systems, with CNC-machined copper and copper alloy components being widely used. High-precision copper parts (such as charging gun terminals and battery connection pins) ensure stable current transmission. In the battery system, CNC-machined copper tabs and busbars efficiently collect power, while copper sleeves precisely adapt to the heat dissipation structure, balancing electrical and thermal conductivity. In the cooling system, precision-machined copper tubes, with their excellent dimensional accuracy, ensure reliable heat dissipation under high-voltage environments. Connectors and sensor contacts made from brass and other alloys, manufactured through CNC machining, maintain excellent conductivity while meeting complex assembly requirements through high-precision morphology, fully supporting the efficient operation of the vehicle's power transmission and thermal management systems.

▶ Low carbon steel (carbon content <0.25%) is a "frequent visitor" in the industrial field and also occupies an important position in CNC processing.

Its strength and toughness are balanced, and the cutting force during processing is moderate, which is suitable for various conventional processing technologies. Low carbon steel is cheap and the raw material supply is sufficient, which is suitable for mass production of structural parts, such as chassis brackets in auto parts and gear blanks in mechanical transmission. After heat treatment, low carbon steel can also improve the surface hardness and meet the wear resistance requirements.

However, it should be noted that low carbon steel is easy to rust, and usually needs to be electroplated or painted after processing; and its thermal conductivity is not as good as aluminum alloy, so it needs to be cooled during high-speed processing to avoid deformation of parts.

▶ In scenarios with high requirements for corrosion resistance, 304 and 316 stainless steel are the first choice for CNC machining.

304 stainless steel contains chromium-nickel alloy, has strong oxidation resistance and stable processing performance, and is suitable for making parts for food machinery and medical equipment; 316 stainless steel has better resistance to salt spray and high temperature corrosion due to the addition of molybdenum, and is often used in aerospace pipeline systems and exhaust parts in auto parts.

Although stainless steel has a high hardness (about 150-200HB) and the tool wears faster during cutting, high-precision parts can still be efficiently processed by selecting carbide tools and optimizing cutting parameters (such as reducing feed speed and strengthening cooling).

▶ To determine whether a metal is suitable for CNC machining, the following factors need to be considered comprehensively:

• Machining efficiency: Material hardness and cutting resistance directly affect machining speed and tool life;

• Precision control: Thermal conductivity and plasticity determine whether the parts are easily deformed due to machining heat or stress;

• Cost adaptation: Raw material prices, machining energy consumption, and subsequent processing costs must match the project budget;

• Scenario requirements: The strength, corrosion resistance, weight and other properties of the parts must meet the special requirements of the application field (such as the requirements of aerospace for lightweight and high temperature resistance).

Different metals have their own advantages, and the selection needs to be combined with the drawing requirements, performance indicators and cost budget of the specific project. If you are struggling with the selection of parts, or want to know the feasibility of machining a certain metal, please contact us. Our team of engineers is familiar with the machining characteristics of various metals and can provide customized solutions according to your needs, from material selection to process optimization, to escort your project throughout the process.