5-Axis Machining Centre inspection and measurement methods

5-Axis Machining Centre is a machining centre that can orient the cutter or the workpiece on two additional rotary axes. It is used for parts with compound angles, deep cavities and features that would otherwise need several setups. This entry explains what it is, what the numbers on a data sheet mean, and what to put on a drawing.
It is written from the point of view of the buyer and the drawing office: the values that are realistic in production, the ones that cost money, and the way the result is verified. Where an industry sets the requirement, automotive is used as the example: a fixed takt, because a late delivery stops the line.
How it is measured
CMM with a five axis probe head, or structured light scanning for free form faces. The equipment is calibrated, the uncertainty is recorded, and the part is at room temperature before the first point is taken.
| Specification | Typical value |
|---|---|
| Characteristic | Method |
| Size | gauge or CMM, to the drawing tolerance |
| Geometry | CMM evaluated against the datum frame |
| Surface | Ra 0.8 µm achievable with a finishing pass |
| Material | AS9100 with material traceability |
| Tolerance | ±0.01 mm |
What the report contains
- Every feature called up on the drawing, with a measured value rather than a tick.
- The datum order used, so the report can be reproduced.
- The certificate reference for the material and the calibration dates for the equipment.
Common sources of dispute
Most disagreements are about method, not about the part: a warm part, a burr left on, or a datum taken in a different order. Avoid deep narrow cavities that force a long thin holder

Applications
5-Axis Machining Centre is used for parts with compound angles, deep cavities and features that would otherwise need several setups, and in practice it appears most often in impellers and blisks, aerospace structural parts, medical implant trials, mould cores.
How it fits into a machining route
5-Axis Machining Centre is one station in a route rather than the whole of it. The part arrives with the previous operation finished and leaves with the features it is responsible for completed, so the datum and the clamping method are agreed before the first part rather than discovered on it.The route is fixed before the first part is cut, and it is the route rather than the individual setting that holds the result: programming time and simulation, not machine hourly rate. Where a drawing calls for something the route cannot hold economically, that is raised at quotation rather than after the parts are made.
Standards, documentation and what is issued
The documentation requirement is AS9100 with material traceability. Material is supplied against a certificate where the application calls for it, inspection results are recorded with the job, and the records are kept so that a repeat order can be compared with the first instead of being measured from scratch.
CMM with a five axis probe head, or structured light scanning for free form faces is the verification step. Where a customer format or a standard report is required, it is agreed before the batch starts, because a report written after the event is a report nobody can use.
Frequently asked questions
What tolerance should be specified for 5-Axis Machining Centre?
±0.01 mm is realistic in production. Tightening it beyond the functional requirement increases cost without improving the part.
Which material is usually used?
Ti-6Al-4V titanium is the usual choice, supplied against AS9100 with material traceability.
How is the result verified?
CMM with a five axis probe head, or structured light scanning for free form faces, with the results recorded so a repeat order can be compared with the first.
What is the most common mistake?
Collision between the holder and the part, which only shows up in a simulation.
How long does it take and what does it cost?
A realistic cycle is 40 to 120 minutes for a complex part, and the cost driver is programming time and simulation, not machine hourly rate.

Related capability
If you are specifying 5-Axis Machining Centre on a drawing and want a second opinion on the route, send the model and the quantity. The first response is a manufacturability review with the likely risk points and a quotation, so the decision can be made on facts rather than on a price alone.
Machining, inspection and documentation are handled in one place, which is why the dimensional report and the material certificate arrive with the parts rather than after them.
Related entries
These entries sit next to 5-Axis Machining Centre in the encyclopedia: Vertical Machining Centre, Horizontal Machining Centre, CNC Milling. Reading them together gives a fuller picture of how the process, the material and the measurement affect each other.