CNC milling service · 5-axis machining
CNC milling and 5-axis machining service
A CNC milling service for custom milled parts on 3, 4 and 5-axis machines: housings, brackets, manifolds and multi-face parts in aluminum, steel, titanium and plastics, ±0.03 mm standard, from 1 piece.
Custom CNC milled parts from your CAD
Milling removes material with a rotating cutter while the part is held in a vise or fixture. It is the default process for prismatic parts: anything with flat faces, pockets, slots, bosses, bolt patterns and contoured surfaces. Typical work through our CNC milling service includes electronics enclosures, sensor and motor brackets, heat sinks, hydraulic and pneumatic manifolds, fixtures, adapter plates and optical mounts.
Upload STEP plus a drawing. An engineer quotes within 12 hours, chooses 3-axis, 4-axis or 5-axis based on the geometry, and adds DFM notes where a small change saves a setup or a special tool. Parts are made in up to 7 days, or 3–4 days expedited, and inspected against your drawing before shipping. Standard tolerance is ±0.03 mm; tighter tolerances on critical features are confirmed in the quote.
- Materials: aluminum 6061-T6, 7075-T6, 5052, 2024; stainless 303, 304, 316, 17-4PH; steel 1018, 1045, 4140; brass C360; copper C110; titanium Grade 2 and Grade 5; POM, PEEK, nylon, PC, ABS, PTFE. See materials.
- Finishes: as machined (Ra 3.2 µm typical), bead blasted, anodized Type II and Type III, powder coated, passivated, plated, polished, laser marked.
- Quantities: 1 piece to around 1,000 pieces.
3-axis vs 5-axis CNC machining: when to pay for more axes
More axes are not automatically better. Each extra axis reduces the number of times the part is re-clamped, but 5-axis machine time costs more and programming takes longer. The question is how many setups the part needs on a 3-axis machine, and whether the geometry can be reached at all.
| Method | How it works | Good for | Pay for it when |
|---|---|---|---|
| 3-axis | Tool moves X, Y, Z; part fixed. One face per setup. | Plates, brackets, pockets and holes on 1–2 faces | Default. Cheapest per hour, simplest to program. |
| 4-axis | Adds rotation (A axis) around one horizontal axis. | Features around a cylinder or on 4 sides of a block | Holes or slots on several sides that share one rotation axis. |
| 3+2 (positional 5-axis) | Two rotary axes tilt the part, then lock; cutting is 3-axis. | Angled holes and faces, 5 sides in one clamping | Parts that would need 4+ setups on 3-axis, or where position between faces matters. |
| 5-axis simultaneous | All five axes move together while cutting. | Impellers, blades, free-form and organic surfaces, deep undercuts | Only when the surface itself cannot be cut with a fixed tool angle. |
For most engineering parts, 3+2 delivers the main benefit of 5-axis CNC machining services: fewer setups, so features on different faces are positioned relative to one datum rather than re-indicated after each re-clamp. That matters when a hole on the side must line up with a pocket on top within a few hundredths of a millimeter. True simultaneous 5-axis is needed for sculpted surfaces, not for a bracket with an angled hole.
You do not need to specify the machine. Send the model and mark the critical relationships on the drawing; we select the method in the quote and say why.
Design tips for CNC milled parts
Most of the cost of a milled part is machine time and setups. These rules keep both down without changing function.
Internal corner radii
A rotating cutter always leaves a radius in vertical internal corners. Make the radius at least one third of the pocket depth, and slightly larger than a standard cutter radius (for example R3.2 rather than R3.0 for a 6 mm tool) so the tool can sweep the corner instead of plunging into it. If a mating square part must fit, use dog-bone or T-bone relief instead of a sharp corner.
Pocket depth to width
Keep pocket depth under about 4× the tool diameter, which in practice means depth no more than 3–4× the narrowest width. Deeper pockets need long-reach tools that deflect and chatter, so they cut slower and hold tolerance worse.
Thin walls
Aim for walls of at least 0.8 mm (0.03 in) in metals and 1.5 mm (0.06 in) in plastics. Thinner walls vibrate during cutting and can move after release from the vise. Tall thin walls are worse than short ones; keep height-to-thickness under roughly 10:1 where possible.
Holes
Use standard drill sizes where a hole is not toleranced, and call out reamed or bored fits (H7 and so on) only where a pin or bearing fits. Drilled depth beyond about 4× diameter slows the job; beyond 10× it needs special tooling.
Threads
Thread depth of 1.5× the nominal diameter gives nearly full strength; deeper threads add time without adding holding power. Leave some unthreaded depth at the bottom of blind holes for the tap. Specify the standard (M6×1.0, 1/4-20 UNC) and any helical inserts on the drawing.
Tolerances and text
Apply tight tolerances only to functional features and let the rest follow a general tolerance such as ISO 2768-m. Engraved text should be recessed, not raised, and at least 0.5 mm deep with a sans-serif font. More detail is in our CNC machining tolerances guide and CNC machining cost guide.
Related
Other processes and services
CNC turning
Round parts, shafts and fittings, with milled flats and cross holes.
From 1 pcRapid prototyping
Milled prototypes in production materials, 3–4 days expedited.
10 – 1,000 pcsLow-volume production
Repeat the approved process for batches with first-article approval.
Blast · anodize · coatSurface finishes
Finish options for milled aluminum, steel and stainless parts.
FAQ
CNC milling questions
Is 5-axis machining more expensive than 3-axis?
Per hour, yes. Per part, not always: if 5-axis replaces three or four separate 3-axis setups, the total can be similar or lower, and feature-to-feature accuracy improves. We choose the method that gives the lowest cost for the tolerances on your drawing.
What tolerance can CNC milling hold?
Our standard is ±0.03 mm. Tighter tolerances on critical features are possible when called out on the drawing and confirmed in the quote. See the tolerances guide.
What is the smallest internal corner radius you can mill?
It depends on pocket depth, because small cutters are short. A good rule is a radius of at least one third of the depth. Sharper corners need EDM or a different design, so use dog-bone relief where a square part must fit.
Can you mill one part only?
Yes. The minimum order is 1 piece, and runs go up to around 1,000 pieces.
What is the difference between 3+2 and simultaneous 5-axis?
In 3+2 the part is tilted to a fixed angle and then cut with 3 moving axes. In simultaneous 5-axis all axes move during the cut, which is needed only for free-form surfaces such as impellers or blades.