When selecting materials for CNC machined parts, one of the most common questions engineers ask is:
“Should I choose steel CNC machining or aluminum CNC machining?”
Both materials are widely used in CNC machining manufacturing, but they differ significantly in cost, strength, machinability, and application. This guide provides a clear comparison of steel vs aluminum CNC machining, helping buyers make cost-effective and performance-driven decisions.
| Factor | Aluminum CNC Machining | Steel CNC Machining |
|---|---|---|
| Machinability | Excellent | Moderate |
| Strength | Medium | High |
| Weight | Lightweight | Heavy |
| CNC Machining Cost | Lower | Higher |
| Tool Wear | Low | High |
| Typical Lead Time | Short | Longer |
Understanding these differences is critical for controlling CNC machining price and ensuring part performance.
Aluminum is one of the most popular CNC materials for CNC milling aluminum parts factory due to its balance of performance and cost.
Fast machining speeds
Lower CNC machining cost
Lightweight and corrosion-resistant
Excellent for CNC milling and CNC turning
Wide availability in China CNC machining shops
Lower strength compared to steel
Not ideal for extreme load or wear conditions
Aluminum 6061: Cost-effective, general-purpose
Aluminum 7075: High strength, motorsport and aerospace
Aluminum 5052: Corrosion resistance
Steel CNC machining is used when strength, durability, and wear resistance are critical.
High tensile strength
Excellent wear resistance
Suitable for structural CNC machine parts
Ideal for heavy-duty applications
Higher CNC machining price
Longer machining time
Increased tool wear
Heavier part weight
Carbon steel (1018, 1045)
Alloy steel (4140, 4340)
Stainless steel CNC machining (304, 316)
Faster cutting speeds
Lower tool wear
Shorter machining time
Easier surface finishing
Slower feeds and speeds
More expensive tooling
Additional finishing and inspection
Longer production cycles
In most cases, aluminum CNC machining reduces total CNC machining cost by 30–50% compared to steel.
| Property | Aluminum | Steel |
|---|---|---|
| Tensile Strength | Lower | Higher |
| Fatigue Resistance | Moderate | High |
| Corrosion Resistance | Good | Depends on grade |
| Heat Resistance | Moderate | High |
For high-load or safety-critical components, steel CNC machining is often the better choice.
Both materials support:
CNC milling machining
CNC turning and lathe machining parts
3 axis, 4 axis, and 5 axis cnc machining services
However:
Aluminum is ideal for high-speed CNC milling
Steel often requires rigid setups and advanced CNC machine parts
Material choice directly affects CNC machining service efficiency.
Automotive CNC machining (lightweight parts)
CNC motorsport and racing
Electronics enclosures
CNC machine parts requiring low weight
Cost-sensitive custom machined parts
Heavy machinery components
Structural parts
High-wear industrial parts
Safety-critical applications
In many cases, yes.
Replacing steel with aluminum CNC machining is possible when:
Load requirements are moderate
Weight reduction is beneficial
Corrosion resistance is needed
CNC machining price is a concern
Engineering evaluation is essential before material substitution.
If steel CNC machining is required:
Avoid unnecessary tight tolerances
Use carbon steel instead of stainless steel where possible
Optimize part geometry
Combine orders to reduce setup cost
These steps help control CNC machining cost even with steel.
For many applications, yes—especially when using aluminum 7075.
Yes, due to longer machining time and higher tool wear.
Both can achieve high precision; aluminum is easier and more cost-effective.
Yes. China CNC machining manufacturers offer extensive steel CNC machining services.
Both steel CNC machining and aluminum CNC machining play critical roles in CNC manufacturing. Aluminum offers lower cost and faster production, while steel provides superior strength and durability.
Choosing the right material helps balance performance, CNC machining price, and lead time.
Hey there, I'm Ming!
From MQJM, I'm a CNC machining expert with over 20 years of experience. We provide high-quality and high-precision machining services in China. Ask for a quote for your ongoing or upcoming projects now!
Best Regards, Ming, Co-Founder
