Last Updated: March 2026
5-Axis CNC Machining: When You Need It and When You Don't
Most CNC machined parts do not need 5-axis machining. Prismatic parts with features on up to six faces can typically be done on a 3-axis machine in two to four setups at lower cost. 5-axis machining (both 3+2 positional and simultaneous) is genuinely necessary for compound angles, turbine/impeller geometry, complex sculptural surfaces, and parts where single-setup accuracy is critical. Understanding which category your part falls into directly affects your quote.
Understanding CNC Machining Axes
3-Axis
Tool moves in three perpendicular linear directions. Can machine the top face of a workpiece and any vertical walls accessible from above. Multiple setups needed for features on different faces.
3+2 (Positional 5-Axis)
Workpiece is tilted to an angle using two rotary axes, then machined with 3-axis motion. Allows access to multiple faces and angled features in fewer setups. Rotary axes do not move during cutting.
Simultaneous 5-Axis
All five axes move during the cut. Enables continuous tool contact on complex curved surfaces, constant tool tilt for optimal cutting, and geometry impossible on any other machine.
When You Genuinely Need 5-Axis Machining
- →Compound angles
A feature that is angled in two planes simultaneously (e.g., a hole that is 15° from vertical and 30° from the X-axis) cannot be achieved on a 3-axis machine without specialised angled fixtures. 3+2 machining handles this cleanly.
- →Single-setup dimensional accuracy
When multiple features must be precisely located relative to each other across different faces (e.g., two bearing bores on non-parallel faces within ±0.01mm concentricity), doing this in a single 5-axis setup eliminates fixturing errors between setups.
- →Turbine and impeller geometry
Bladed components with swept, twisted geometry require simultaneous 5-axis machining to maintain consistent tool engagement and surface finish across the blade surface.
- →Deep mould cavities and electrodes
Deep mould cavities with complex draft surfaces benefit from 5-axis to maintain perpendicular tool engagement (reducing tool deflection and improving surface finish).
- →Complex sculptural and organic surfaces
Medical implants, prosthetics, and organic industrial design parts with smooth compound curvature require simultaneous 5-axis to machine efficiently.
When 3-Axis Is Sufficient
Many parts initially quoted for 5-axis can be machined on a 3-axis machine with appropriate fixturing, at lower cost:
- Prismatic parts with features on multiple faces
3-axis with multiple setups (flip and re-fixture). Practical if setups are ≤3 and tolerances between faces are ≥±0.1mm.
- Simple angled holes (one angle direction)
Use an angled fixture block on a 3-axis machine. Cheaper than 5-axis for small quantities.
- Parts with features on all six faces
Four to six 3-axis setups often still cheaper than 5-axis if tolerances between setups are moderate.
- Parts designed for 5-axis that can be simplified
DFM review sometimes reveals that compound angles can be converted to single-plane angles, removing the 5-axis requirement entirely.
Cost Comparison: 3-Axis vs 5-Axis
| Factor | 3-Axis | 3+2 (Positional) | Simultaneous 5-Axis |
|---|---|---|---|
| Machine hourly rate | Base ($) | +20–40% | +50–100% |
| Programming time | Low | Moderate | High |
| Setup time | Low per setup | Moderate | Moderate–high |
| Setups required (typical) | 2–4 | 1–2 | 1 |
| Dimensional accuracy between features | Affected by re-fixturing | Good | Excellent |
| Surface finish on complex curves | Stepped (faceted) | Good | Excellent |
Industries Requiring 5-Axis Machining
5-Axis Machining Through Rapid Manufacturing
Rapid Manufacturing's supplier network includes 5-axis machining centres capable of both 3+2 positional and simultaneous 5-axis work. Our engineering team reviews every submission and determines the most cost-effective machining strategy — including whether 5-axis is genuinely required or whether a redesign or multi-setup 3-axis approach is more economical.
All 5-axis suppliers in our network hold ISO 9001:2015 certification. Aerospace-grade suppliers with AS9100-D certification are available for qualifying components.
Quote Your 5-Axis Part
Upload your STEP file. Rapid Manufacturing's team will assess whether 5-axis is required and return an optimised quote within 2 business days.
Get a QuoteFrequently Asked Questions
What is 5-axis CNC machining?
5-axis CNC machining moves the cutting tool (or workpiece) along five simultaneous axes: the three linear axes (X, Y, Z) plus two rotational axes (A and B, or A and C depending on machine configuration). This allows the tool to approach the workpiece from virtually any angle, enabling machining of complex geometry that would be impossible or require many setups on a 3-axis machine.
What is the difference between 3+2 and simultaneous 5-axis machining?
3+2 axis machining (also called positional 5-axis) positions the workpiece at an angle using two rotational axes, then machines with the 3 linear axes — the rotational axes do not move during the cut. This is much cheaper than simultaneous 5-axis and handles the majority of "5-axis" requirements. Simultaneous 5-axis moves all five axes at the same time, required only for truly complex geometry like turbine blades, impellers, and sculptural medical implant surfaces.
How much more expensive is 5-axis machining than 3-axis?
3+2 machining typically adds 20–40% to part cost compared to pure 3-axis, mainly due to higher machine rates and programming time. Simultaneous 5-axis adds 50–150% or more, depending on part complexity. However, for parts that genuinely require 5-axis, the alternative (multiple 3-axis setups with associated fixturing and tolerance stack-up) can actually be more expensive.
Does Rapid Manufacturing offer 5-axis CNC machining in Australia?
Yes. Rapid Manufacturing's supplier network includes 5-axis CNC machining centres for both 3+2 positional and simultaneous 5-axis work. This includes aerospace components, medical device parts, mould cavities, and complex structural components. Submit your STEP file for a quote and our team will determine the optimal machining strategy.
What industries typically require 5-axis machining?
The main industries requiring true 5-axis machining are: (1) Aerospace — complex structural parts, turbine blades, impellers. (2) Medical — complex implant geometries, surgical instruments. (3) Mould and die — complex mould cavities, cores, and electrodes. (4) Energy — pump housings, impellers, turbine components. (5) Motorsport — suspension components, engine parts with compound angles.
Can I redesign my part to avoid 5-axis machining?
Sometimes yes, sometimes no. Features that genuinely require 5-axis include: compound angles (angles in two planes simultaneously), features on multiple non-parallel faces, and undercuts that can only be reached by tilting the tool. Features that can often be redesigned to avoid 5-axis: angled holes (can sometimes be done in 3-axis with angled fixtures), complex fillets (can sometimes be replaced by simpler geometry). Rapid Manufacturing's free DFM analysis will flag 5-axis requirements and advise on redesign options.