CNC Machining Cost Calculation: A Complete Guide

CNC machining is one of the most efficient methods of production for high precision machining. This is due to many benefits associated with this technique such as high quality, faster lead time, high dimension accuracy, production efficiency and many more. Along with that, the cost of CNC machining also depends on many factors. So, let’s dive into the detail of how to calculate CNC machining and how to save cost with maximum benefits.

What is CNC Machining and Why is Cost Calculation Important?

CNC machine is an automated production method that uses computer numerical control (CNC) machines. They precisely shape parts from solid blocks of metal, plastic, wood or composite to create highly detailed complex parts. Cost calculation is very crucial in CNC Machining as it depends on many factors like design complexity, material selection, machining time, and quantity of parts.

What is CNC?

CNC machine stands for "Computer Numerical Control" machine. A computer aided program control the precise movement of cutting tools to create parts from material removal process with higher production efficiency. Parts produced with high accuracy and have consistent production of intricate shapes with no human error.

Understanding CNC Machining Cost Calculation

CNC machining cost is calculated by adding cost of raw material, tool costs, machining time, post-processing procedures like finishing, overhead cost and profit margin at final price per part.

The Importance of Accurate Machining Cost Calculation

Accurate machining cost allows proper pricing, better decision-making for project feasibility, profit optimization, competitive bidding and cost control by giving a clear understanding of the costs of machined parts.

Why are CNC Machining Parts so Expensive?

CNC machined parts are costly because of using specialized machinery and tooling and skilled labor and experienced staff to handle the operation. It also includes design complexity, cost of raw material, and additional finishing procedures which impacts the substantial overall manufacturing costs.

Material Selection and Its Impact on Machining Cost

Material selection directly impacts the price of raw material, machinability or operational process like cutting or shaping, specialized tools, and other factors like harder material require more times or tool wear leads to overall cost. Therefore, material selection balances the costs, and performance is key to control machining costs.

Part Design and Complexity

Part designs and complexity is a key consideration of CNC machining process because lead time and cost are major factor here. Design complexity includes tight tolerance, intricate geometry and multiple features of part like size, weight, wall thickness, surface curvature, and part finishing.

Volume of Production

volume production is the number of parts a CNC machine can produce within a specific timeframe. It is normally measured in "parts per hour". Cost factors involved here are design complexity, material selection, machine capacity for production, from a few dozen parts/hr for intricate designs to hundreds for simpler parts.

Machine Type and CNC Machine Price

Machine type plays an important role in the price of machines such as CNC lathe, CNC mil, laser cut and then its size capabilities, features and models that can range from thousands of dollars for entry level models to hundreds of thousands of dollars for high-end features and models.

Labor Costs

Labor costs are basically the wages paid to CNC machinist. It is normally calculated in hourly rate which can charge large portion of labor cost and then it includes design complexity, skill level of machinist, and machine time that are involved in labor cost.

Time and Machine Operating Time

Time refers to the total time taken to complete a machining process. It includes setup time of machines, machine program execution time, tool changes, cutting time and machine operating time when the machining of part starts. It does not involve tool change time or pauses in operations.

Surface Finishing and Additional Processes

The surface finishing process in CNC machining is bead blasting, powder coating, electroplating, anodizing, or grinding to improve corrosion resistance, wear resistance and to get other desired outcomes. These are all advanced processes and can have higher cost per unit.

Machine Shop Rates

These rates can differ from machine type, location or design complexity. However, it generally ranged from $30 to $100 per hour with a typical 3-axis CNC milling machine. Advanced multi-axis machines can cost higher.

How to Calculate CNC Machining Costs

The important points to consider while calculating the CNC machining cost are explained below:

What Does CNC Machining Cost Per Hour?

The calculation for cost per hour for CNC machining includes machine type, quantity, material selection, project complexity and finishing process. Normally, CNC machining per hour can range from $5–$200 per hour.

CNC Machine Hourly Rates Explained

The CNC machine hourly rate includes cost charged per hour of machine operation like deep hole machining or thin wall machining depending on type of machine (3-axis vs. 5-axis), the design, material and the level of expertise required. The high-end machines and complicated designs have higher hourly rates.

How to Calculate CNC Machining Costs Per Hour

To calculate CNC machine cost per hour:

• Divide the total cost estimation of ownership of CNC machine by the number of hours
• The number of hours is normally taken from a year with factors including machine purchase price, maintenance costs, depreciation, labor costs, and tooling expenses.
• The "machine hour rate" is by dividing the total cost by the total usable hours

Factors Affecting Hourly Rates

There are serval factors that can affect the hourly rate of CNC machining

Material Costs

The cost estimation of raw material includes material selection like metal, plastic or wood. For example, aluminum is cheaper than steel and titanium. High-performance material has higher cost of processing per unit weight.

CNC Machine Operating Costs

Operating costs analysis includes labor cost, raw material, tooling, machining time and design complexity. Normally, a 3-axis machine can cost between £25-£50/hr and a 5-axis machine can cost between £50-£100/hour

Programming and Setup Costs

Programming and setup costs include machine capabilities, hourly rate, location, and time spent designing the part, setting up the machine, tools and fixture and perform initial test cut. It can range from $30 to $100 per hour for a 3-axis machine. Cost increases with the change of machine type.

Cost of Goods Manufactured

It includes the cost of raw material, labor cost and additional manufacturing cost like tooling, setting up, post-processing procedures etc.

Quality Control and Inspections

It includes the cost of level of high precision machining requirements, inspection method like manual gauging or CMM, quality standards of shop and complexity of part.

Using CNC Machining Cost Calculators

CNC machining cost calculator and tools helps to calculate the total cost of machined parts with material selection, part complexity, machining time, tooling costs and overhead costs.

CNC Machining vs. 3D Printing: Which Is More Cost-Effective?

CNC machine is better for high-volume production. The cost per unit is less in CNC machining than 3D printing. 3D printing is constant for cost per part, but it is more suitable for prototyping and low production volume.

CNC vs. 3D Printing: Cost Comparison Per Unit

CNC machining becomes more cost effective as the volume of production increases. The cost decreases with the large amount of volume. 3D printing is regardless of number or unit of volume. It remains the same and constant for any volume

When to Choose CNC Machining Over 3D Printing

For large volume production, choose CNC machining. For prototyping and small volume production, 3d printing is best

The Cost of CNC Cutting vs. 3D Printing for Complex Parts

3D printing is more suitable for complex parts as it is low material wastage. But it is only suitable for prototyping or small volume.

Reducing CNC Machining Costs: Best Practices and Strategies

There are a few strategies that reduce the machining cost if used properly.

Design Optimization for Cost Savings

The optimization of design for manufacturing includes using simple designs, the right selection of materials and limiting the number of machine setups can have cost reduction

Choosing the Right Materials

Choosing cost-effective material by considering factors such as machinability and application can have cost reduction. The suitable materials are aluminum, mild steel, brass, copper and stainless steel and plastics ABS and POM

Minimizing Surface Finishes

To minimize surface finishes for cost savings in CNC machining,

• use standard surface roughness values,
• avoiding unnecessary finishes,
• choosing appropriate toolpaths
• and selecting materials with good surface quality

CNC Milling vs. CNC Turning vs CNC Milling & Milling

CNC turning is more cost effective for simple and cylindrical parts with faster machine time. CNC milling is better for complex and intricate geometries

Volume Production vs. Custom Machining

Volume production is generally more cost-saving. Custom machining involves high initial setup costs and is more suitable for small production volume or prototypes.

Outsourcing vs. In-House CNC Machining

Outsourcing CNC machining is more cost effective as it does not involve large upfront investment, labor training, and maintenance cost and only need to pay primarily for the service

Automation to Reduce Business Expenses

Automation can have cost reduction for overall business expenses by reducing manual work, streamlining procedures and improving efficiency. It can be AI automation, IT automation, business process automation and automated inventory management.

CNC Machining Cost Calculation for Different Applications

To know the CNC machining costs estimation for different applications, consider factors material type, machine type, part complexity, quantity, tooling requirements, and finishing operations. This is basically the material cost, machining cost and labor cost.

CNC Machining Cost for Car Parts

Auto parts significantly have higher machining prices due to high-end part design, material selection, volume of production, specialized tooling and tight tolerance leads to an increase in the cost of car parts.

CNC Milling Cost vs. CNC Turning Cost

Normally, the operating cost of CNC turning is cheaper than CNC milling. It is because it has simple machine operations, faster production rate and low initial cost than CNC lathe, CNC milling and other operations like deep hole machining or thin wall machining for similar parts. CNC tuning offers low cost per unit.

Machining Costs for Small vs. Large Parts

Machining costs estimation are always higher for larger parts due to high material usage, longer machining time, specialized tooling to handle larger dimensions which results in overall high cost per unit than for small parts

Using Job Costing for CNC Machining: How It Can Help You Stay Within Budget

Job costing helps to track and assign all the cost associated with specific machine cost, raw material, labor cost, tooling cost, setup time and overhead cost.

What is Job Costing?

Job costing is to accurately calculate the total cost of producing a batch by tracking all associated expenses. These include cost of raw materials, labor cost, tooling, machine time, labor, tooling, and any additional overhead costs. It allows precise pricing and profit analysis for a specific production batch.

How to Apply Job Costing for Accurate CNC Price Estimation

Job costing is applied by breaking down the total cost of CNC machining project into smaller tasks and then adding a profit margin at final price. It allows us to account for specific complexities of each job and machine used.

Machining Job Costing for Complex Parts

To get the cost analysis of CNC machining cost per unit for multi-axis and custom parts, consider the cost of machining, expected annual operating hours, labor, material, set-up time, programming time, tooling, design complexity, and quality control procedures, then divide the total cost by the estimated machining time/ piece.

How Tuofa CNC Machining Can Help You Save on Costs

Tuofa CNC machining offers best service in China that can help you to save your cost in CNC machining by providing high precision machining and higher production efficiency which allows for optimized material usage, streamlined design for manufacturing (DFM), reduce material waste, and to ability to leverage economies of scale by bulk orders. These all ultimately will result in cost reduction for your cost per unit if you get services from Tuofa CNC machining.

Conclusion

CNC machining cost analysis includes a sum of the cost of raw material, machine type, labor cost, tooling cost, machining setup and processing time, finishing process, additional quality control procedure and profit margin. It is basically a sum of material cost, labor cost and operational cost like deep hole machining or thin wall machining with their machining time. CNC machining cost can be optimized by choosing less complex design, high production volume, small part size and choosing cost-effective material.