Why Is CNC Machining So Expensive? A Breakdown of Costs and How to Reduce Them
CNC machining costs are primarily made up of four main components:
Equipment Depreciation
Consumables
Labor Costs
Factory Rent and Overhead
Because each factory has different operational costs, the same part may receive different price quotes from different manufacturers.
- Equipment Depreciation
This refers to the annual depreciation of CNC machines based on their purchase price, usually calculated over a 10-year lifespan.
Example:
If a machine costs 1.2 million yuan, the yearly depreciation would be 120,000 yuan, or 10,000 yuan per month.
If your batch of parts requires three days of machining on that machine, the depreciation cost is about 1,000 yuan.
Note: If multiple machines are involved (e.g. CNC, testing equipment), the depreciation from each must be calculated.
- Consumables
Consumables include:
Raw materials
Cutting tools
Lubricants, coolant, and other fluids
Tool wear and replacements
Example:
If you use 100 pieces of 45# steel to produce shafts, that’s your raw material cost.
During machining, you may also wear out:
Two cutting tools
A certain amount of lubricant and coolant
These costs collectively form the consumables.
- Labor Costs
This includes the time spent on:
Machine setup and operation
Quality control
Programming (if applicable)
Example:
If three workers spend three days on a batch of parts, the labor cost is based on their daily wages multiplied by 3 people × 3 days.
In larger factories, dedicated QC inspectors and engineers may be involved, which increases labor costs further.
- Factory Rent and Utilities
This refers to:
Factory space rent
Electricity, water, and other utilities
General operating expenses
Rent is not calculated strictly per part, but instead distributed across all ongoing projects.
This is why most factories are located in suburban or industrial zones where rent is lower.
How to Reduce CNC Machining Costs
Here are practical ways to reduce costs during design and sourcing:
✅ 1. Loosen Tolerances Where Possible
Design for functionality, not over-precision.
If two parts are simply bolted together and do not require high positioning accuracy, the through-hole diameter can be increased, and tolerance relaxed.
Don’t blindly follow standard tolerance tables—match tolerances to the real-world function.
This can eliminate secondary finishing operations and reduce processing time.
✅ 2. Design for Single Setup Machining
Try to combine steps to reduce tool changes and re-positioning.
For example:
Design stepped holes as through-holes
Use wire EDM instead of complex milling where applicable
Setup and calibration often take longer than the actual cutting. Reducing setups = reducing costs.
✅ 3. Use Functional Testing Instead of Precision Measuring
Instead of checking tight tolerances on a CMM or measuring tool, sometimes it’s faster to test with the mating part.
Example:
If your part has two bosses that must fit into another part, simply try assembling them to check fit, rather than measuring exact positions.
✅ 4. Avoid Over-Specifying Equipment
Don’t default to high-end machines like 5-axis or 6-axis unless truly necessary.
If the job can be done with a standard 3-axis machine, go for it.
High-end machines increase costs even for simple parts.
✅ 5. Consider Additive Manufacturing (3D Printing)
For small batches with:
Complex geometries
Low tolerance requirements
Other Industry Insights
Prototype Manufacturing Methods:
Manual
CNC
RP (Rapid Prototyping like SLA/SLS/3D printing)
Hybrid
CNC dominates, but other methods are equally important, especially as technology advances.
Easy to machine and bond
Retains strength after gluing
Why One-Off CNC Parts Are Expensive
Many wonder why making just one part costs so much. Here’s why:
No economies of scale
Programming, setup, material sourcing, and QC are the same whether it’s 1 or 100 parts
Material loss, inventory handling, scrap, and procurement time must be included
Large factories won’t even quote for one-off orders unless there’s follow-up business
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