Internal corner radii and pocket depths
Include the requirement or identify it as an open question for the project review.
CAPABILITIES
CNC Milling Services for Precision Machined Parts
Our CNC milling service covers prismatic parts, pockets, mounting patterns and contoured faces. The number of setups and the features that must stay related to each other shape how the part is made.
Pockets, mounting patterns and contoured faces.
A rotating cutter removes material from a secured workpiece. Tool access, corner radii and the number of setups affect how a part is made.
Typical part types: Mounting brackets, machined housings and fixtures.
Count the setups before comparing prices
A milled part is held, cut, released and re-held. Every time it is re-held, the relationship between features on different faces has to be re-established. That is why two parts with the same volume of material can be quoted very differently: one is finished in a single setup, the other needs three and a fixture. Identify which faces carry the datums, and which holes or bores must stay in position relative to them.
Tool access decides the rest. A pocket that is deep and narrow, an internal corner smaller than the available cutter, or a bore reached only from an angle all change the route rather than just the cutting time. Mark those features instead of leaving them for the shop floor to interpret.
| Parameter | Planning reference | Why it matters in review |
|---|---|---|
| 3-axis / 4-axis envelope | 1000 × 500 × 500 mm | Workholding and tool reach must both fit the setup |
| General tolerance, 3-axis / 4-axis | ±0.1 mm | Applies where no individual tolerance is stated |
| Recommended metal wall | ≥0.8 mm | A design recommendation, not a limit for every geometry |
| Internal corner radius | ≥ pocket depth ÷ 3 | A rotating cutter always leaves a radius in plan view |
| Hole diameter / preferred depth | Ø ≥1 mm; depth ≤4 × diameter | Deeper holes need a separate tool-access review |
| Pocket depth | ≤4 × pocket width | Preferred ratio of depth to pocket width |
When a part is reviewed for a five-axis route
Some parts have faces at an angle to one another, undercuts, or a contoured surface that a three-axis setup can only reach by re-fixturing several times. Those are the parts we review for the partner-coordinated five-axis route, where a larger envelope of 4000 × 1500 × 600 mm and access to several faces in one setup can hold the relationship between features more directly. Five-axis work is arranged through our partner network, not produced on our own machines.
The planning reference for that route is a general tolerance of ±0.05 mm, against ±0.1 mm for the three- and four-axis setups. Both are general references. Critical features require an individual drawing callout.
Precision CNC machining: mark the features that need it
“Precision” is only useful when it points at specific dimensions. Give an individual tolerance to the bore that takes a bearing, the face that seats against another part and the hole pattern that has to line up with an existing assembly. Leave the remaining dimensions under the general reference so the effort goes where the function is. Our CNC machining overview explains how the route is chosen across milling, turning and specialist processes.
Edge detail deserves the same treatment. The fillet and chamfer guide works through why a top-edge chamfer does not square a pocket corner, and what a measurable callout looks like. Engraved text is two dimensions, not one: Width ≥0.5 mm; depth 0.1 mm.
Material, finish and inspection in the same brief
Choose the alloy with the temper attached. For housings and brackets, compare the options in the aluminum reference or work through the 6061 and 7075 comparison; for bushings and fittings, start with brass. If a surface has a functional requirement rather than an appearance one, state it as a parameter and a limit — the surface roughness reference shows what makes that callout checkable.
Say which dimensions are inspected and whether you need a record with the parts. Quotation within 24 hours.
PREPARE YOUR PROJECT
What a useful brief includes
Datum faces and hole positions
Include the requirement or identify it as an open question for the project review.
Features requiring access from several sides
Include the requirement or identify it as an open question for the project review.
Choose material and finish together.
Identify the application before choosing a grade. Discuss material condition, critical surfaces and whether dimensions apply before or after finishing.
Browse the material libraryScope confirmed during review
- Geometry
- Size, tool access and feature complexity
- Material
- Grade, condition and sourcing requirements
- Quality
- Critical dimensions, surfaces and inspection records
- Delivery
- Quantity, destination and required date
YOUR QUESTIONS, ANSWERED
A clearer path
to your next part.
Find practical answers before starting a project.
Can a milled pocket have sharp internal corners?
A round milling cutter leaves a radius. Increase the corner radius, add a relief or discuss a secondary process if the mating part needs a square corner.
Can you recommend a material or finish?
Choose “Help me choose” in the inquiry. Explain the application and environment so the options can be reviewed against the function of the part.
When are price and delivery confirmed?
We provide a quotation within 24 hours. Estimated delivery is 3–7 days after the order, drawings and required upfront payment are all confirmed: full payment for new customers or the agreed deposit for returning customers. Returning customers pay the balance before shipment.
In-house service
CNC Milling: dimensions & tolerances
These tables provide process-planning references, not measured limits for a specific machine or factory. Dimensions are in millimeters unless stated otherwise. We confirm the usable size, tolerance, material and inspection requirements together in your quotation.
| Parameter | Reference / planning value | Application |
|---|---|---|
| 3-axis / 4-axis envelope | 1000 × 500 × 500 mm | Workholding and tool reach must fit inside the setup. |
| 5-axis envelope | 4000 × 1500 × 600 mm | Setup-dependent; distinguish from the large-part route. Partner-coordinated five-axis route. |
| Minimum part | 5 × 5 × 5 mm | — |
| 3-axis / 4-axis general tolerance | ±0.1 mm | — |
| 5-axis general tolerance | ±0.05 mm | Critical features require an individual drawing callout. Partner-coordinated five-axis route. |
| Recommended metal wall | ≥0.8 mm | Design recommendation, not the absolute minimum for every geometry. |
| Internal corner radius | ≥ pocket depth ÷ 3 | Design recommendation. |
| Hole diameter / preferred depth | Ø ≥1 mm; depth ≤4 × diameter | Deep holes need a separate tool-access review. |
| Pocket depth | ≤4 × pocket width | Preferred design ratio. |
| Thread depth, Ø1.5–5 mm | 3 × diameter | Specify the thread standard and required engagement. |
| Thread depth, Ø>5 mm | 4–6 × diameter | The 5 mm boundary is reviewed with the drawing. |
| Engraved text | Width ≥0.5 mm; depth 0.1 mm | Width and depth are separate dimensions. |
LET’S MAKE IT TANGIBLE
What are you working on?
Bring a drawing. Bring a sketch. Start the conversation.