How Is a CNC Machining Quotation Calculated? Пошаговое руководство

If you’re sourcing CNC-machined parts for your project, understanding how quotations are calculated is key to avoiding overpaying or misinterpreting costs. A CNC machining quotation isn’t a random number—it’s a detailed sum of tangible factors like material use, время обработки, и труд. This guide breaks down the calculation process, core influencing factors, and practical examples to help you verify and optimize quotes.

1. 8 Core Factors That Shape a CNC Machining Quotation

Every line item in a CNC quotation ties back to specific cost drivers. Ниже приведен подробный разбив каждого фактора, with real numbers to illustrate how they impact the final price:

(1) Стоимость материала

Material cost forms the base of the quotation and is calculated by the part’s weight or volume. Different materials have vastly different unit prices, directly affecting this component:

Примечание: Scrap material (typically 10–20% of the raw material weight) is often included in the quotation to account for cutting waste.

(2) Machining Time Cost

Machining time is the single largest variable in most quotations, as it combines equipment and labor charges. It includes three key phases:

• Время программирования: 0.5–2 hours for simple parts (НАПРИМЕР., a flat block) and 3–8 hours for complex parts (НАПРИМЕР., parts with 3D curved surfaces). Programmers typically charge 80–150 RMB/hour.
• Actual Machining Time: Depends on cutting speed, tool path, and part size. A small aluminum part (5cm × 5cm) may take 1–2 hours, while a large stainless steel part (20cm × 20cm) could take 4–8 hours.
• Зажим & Tool Change Time: 0.2–1 hour per part. Multi-sided machining (НАПРИМЕР., 4-axis work) can double this time, adding 0.4–2 hours to the total.

Equipment hourly rates vary by type:

• Ordinary 3-axis CNC machines: 50–100 RMB/hour
• High-end 5-axis CNC machines: 150–300 RMB/hour

(3) Амортизация оборудования

CNC machines cost tens of thousands to millions of RMB, so depreciation is spread over their 5–10-year lifespan and included in the quotation. Например, а 500,000 RMB 3-axis machine has an annual depreciation of 50,000–100,000 RMB, which translates to 20–40 RMB/hour added to the equipment cost.

(4) Обслуживание & Износ инструмента

Инструменты (НАПРИМЕР., Конец мельницы, тренировки) wear out after repeated use and need replacement. A standard carbide end mill costs 50–200 RMB and lasts for 20–50 hours of machining—adding 1–10 RMB/hour to the quotation. Other maintenance costs (lubricating oil, filter changes) add an extra 5–15 RMB/hour.

(5) Labor Cost

Labor covers operators, quality inspectors, and sometimes programmers. Hourly rates vary by region and skill:

• Entry-level operators: 50–80 RMB/hour
• Skilled operators (for 5-axis machines): 100–150 RMB/hour
• Quality inspectors: 80–120 RMB/hour

For a part that takes 3 часы до машины, labor cost typically ranges from 150–450 RMB.

(6) Стоимость постобработки

Most parts require post-processing to meet functional or aesthetic standards, and each step adds to the quotation:

(7) Часть сложности & Точность

Complexity and precision directly increase machining time and skill requirements, pushing quotes higher:

• Simple Parts (block shapes, допуски ±0,1 мм): Lower time and skill needs—quotes are 50–150 RMB/part.
• Сложные части (тонкие стены <2мм, Допуски ± 0,01 мм): Require slower cutting speeds and more programming—quotes jump to 200–1,000 RMB/part.

Пример: A stainless steel part with ±0.01mm tolerance costs 3x more than the same part with ±0.1mm tolerance.

(8) Заказать объем

Batch size unlocks volume discounts, as fixed costs (программирование, настраивать) are spread across more parts. Here’s how volume affects unit quotes for a simple aluminum part:

2. 3 Common Methods to Calculate CNC Machining Quotations

Suppliers use different formulas to compile quotes, depending on part type and order size. Ниже приведены наиболее распространенные методы, with step-by-step examples:

Метод 1: Time-Based Quotation (Most Common for Complex Parts)

This method focuses on total machining time, combining equipment, труд, and other time-related costs.

Формула: Total Quotation = (Equipment Hourly Rate + Labor Hourly Rate) × Total Machining Time + Стоимость материала + Стоимость постобработки

Пример:

• Equipment hourly rate: 100 юаней (3-Ось CNC)
• Labor hourly rate: 60 юаней (operator + inspector)
• Total machining time: 4 часы (1 hour programming + 2.5 hours machining + 0.5 hours clamping)
• Стоимость материала: 40 юаней (0.5kg aluminum alloy × 80 RMB/kg)
• Post-processing cost: 80 юаней (Анодирование)

Total Quotation = (100 + 60) × 4 + 40 + 80 = 160 × 4 + 120 = 640 + 120 = 760 юаней

Метод 2: Material-Based Quotation (Common for Simple Parts)

This method starts with material cost and adds a fixed or variable machining fee.

Формула: Total Quotation = (Material Unit Price × Part Weight) + Machining Fee + Стоимость постобработки

Пример:

• Material unit price: 50 RMB/kg (углеродистая сталь)
• Вес детали: 1kg → Material cost: 50 × 1 = 50 юаней
• Machining fee: 200 юаней (includes equipment, труд, and depreciation for a simple block part)
• Post-processing cost: 50 юаней (бурение 2 отверстия)

Total Quotation = 50 + 200 + 50 = 300 юаней

Метод 3: Fixed Quotation (For Standardized Parts)

For simple, повторяемые части (НАПРИМЕР., spacers, standard fasteners), suppliers often offer a fixed quote that includes all costs. Например:

• A standard aluminum spacer (10mm × 5mm) may have a fixed quote of 20–30 RMB/piece for orders of 100+.
• A stainless steel bolt (M10 × 20mm) could have a fixed quote of 15–25 RMB/piece.

3. How to Verify and Optimize a CNC Machining Quotation

Once you receive a quote, you can cross-check its 合理性 (reasonableness) and reduce costs with these steps:

1. Break down the quote: Ask the supplier to itemize costs (материал, время обработки, пост-обработка) to identify overcharges. Например, if the material cost for a 0.5kg aluminum part is listed as 80 юаней (well above the 25–50 RMB market range), clarify the reason.
2. Оптимизация конструкции детали: Simplify geometry (НАПРИМЕР., replace curved surfaces with straight lines) to cut machining time by 10–30%. Add hollow structures to reduce material weight by 15–25%.
3. Negotiate volume discounts: Even if you need 20 Части сейчас, ask for a “future batch” discount (НАПРИМЕР., 15% off if you order 50+ в пределах 6 месяцы).
4. Adjust precision requirements: Используйте допуск ±0,05 мм вместо ±0,01 мм, если деталь не требует сверхвысокой точности — это может сократить время обработки на 20–40 %..
5. Выбирайте экономичную постобработку: Пропустить ненужные шаги (НАПРИМЕР., полировка внутренних поверхностей, которые не будут видны) сэкономить 50–150 юаней/деталь.

Yigu Technology’s Perspective on CNC Machining Quotations

В Yigu Technology, Мы верим прозрачность – основа доверия в расценках на обработку на станках с ЧПУ. Многие клиенты сталкиваются с проблемами, связанными с расценками «черного ящика», в которых не указаны детализированные затраты., приводя к путанице. Мы всегда разбиваем котировки на материалы, время обработки, труд, и стоимость постобработки, чтобы клиенты точно понимали, куда идут их деньги. We also proactively suggest optimizations: например, if a client requests a stainless steel part with ±0.01mm tolerance for a low-load application, we’ll recommend aluminum alloy with ±0.05mm tolerance—cutting the quote by 30–50% without sacrificing performance. Кроме того, we offer flexible volume discounts, Даже для небольших партий, by aggregating orders from multiple clients. Our goal is to help clients get fair, cost-effective quotes that align with their actual needs.

Часто задаваемые вопросы

1. Why is scrap material included in the material cost of a CNC quotation?

Scrap material (10–20% of the raw material weight) is included because CNC machining produces waste (НАПРИМЕР., черенки, leftover raw material after shaping). Suppliers factor this in to cover the full cost of the raw material they purchase, even if not all of it ends up in the final part.

2. Can I negotiate the machining time cost in a CNC quotation?

Yes—if you can show that the machining time is overestimated. Например, if the quote lists 5 hours for a simple aluminum block (which typically takes 1–2 hours), provide a 3D model or drawing to prove the part’s simplicity. Suppliers may adjust the time to 2–3 hours, lowering the total quote by 40–60%.

3. What’s the difference between a “time-based” and “material-based” quotation?

A time-based quotation focuses on total machining time (combining equipment and labor) and is better for complex parts with variable machining needs. A material-based quotation starts with material cost and adds a fixed machining fee, making it simpler for basic parts (НАПРИМЕР., блоки, spacers) where machining time is predictable. Choose the method that matches your part’s complexity for the most accurate quote.