01
The tolerance floor is unclear
A drawing marked ±0.05 mm on a bearing seat will not hold the fit once the housing is anodized. We see this most on aluminum bores. The fix is a callout that names the mating part, not just a blanket tolerance.
Shop-floor notes
Machinist Resources
Process notes, selection tables and tolerance data pulled from a 127-machine shop floor in Dongguan. Written for the engineer who has to pick a process, a material and a number before the drawing goes out.
±0.005 mm toleranceRa 0.2–0.8 μm finishing1 to 10,000+ partsDFM feedback in 12 hours
15 yearsMachining since 2011
127High-precision CNC machines
4,000 mmMaximum processing size
99.99%Qualification rate
Where projects stall
Four questions that decide whether a part ships
These are the ones we field every week. If any of them is still open on your side, the risk sits in the drawing.
02
Process choice is a guess
Wire EDM, sinker EDM or milling? Each one changes the corner radius, the heat-affected zone and the price. Pick wrong and you pay for a second setup or live with a radius you cannot assemble.
03
Hard alloys eat the schedule
Inconel and 17-4PH cut slower, wear tools faster and move when you release the vise. Without a tool-path and workholding plan, the second week of the schedule disappears.
04
Cost per part is invisible
Quotes arrive as one number. Nobody says how much comes from setup, from material, or from the finish. You cannot negotiate or redesign what you cannot break apart.
How we work
Pick the process, then hold the number
Two capabilities carry most of the work: tight-tolerance turning and milling, and a finishing chain that does not move the datums.
Tolerance
Turning and milling that hold ±0.005 mm
Shafts, bearing seats, splines and housings live or die on the fit. Our 16 simultaneous 5-axis centers and 16 mill-turn centers cut the seat and the mating face in one setup, so the runout does not stack up between operations.
We measure in process, not only at the end. A Ø400 mm rotary table lets us index around a housing without re-chucking, which is where most bore-to-face error creeps in.
- 1±0.005 mmHeld on turned and milled features
- 2Ra 0.2–0.8 μmFine finish on sealing and bearing surfaces
- 3Ø400 mmRotary table for indexed work
Finishing
Finishes that keep the datums where you put them
Anodizing adds a few micrometres. Hardcoat adds more. On a bore that has to accept a bearing, that growth is the difference between a press fit and a scrap part. We mask, we plug, we check the bore after coating.
Powder coating, black oxide, electroless nickel, bead blasting and laser marking all run through the same inspection gate. Laser marking holds a minimum character height of 1.5 mm so the traceability code stays readable after the part is in service.
- 1MaskingBores and threads protected during coating
- 21.5 mmMinimum laser-marked character height
- 3100% inspectionEvery part checked before shipment
Selection
Which process fits the feature
Use this when the drawing has a corner, a slot or a hardened detail that milling cannot reach.
| Feature | Best process | Why |
|---|---|---|
| Sharp internal corner | Wire EDM | Zero-radius corner, no cutter marks |
| Deep blind cavity | Sinker EDM | Electrode reaches what a tool cannot |
| Hardened tool steel | Wire EDM | Cuts after heat treatment |
| Mirror surface | Fine milling + polish | Ra 0.2–0.8 μm on flat faces |
| Thin-wall pocket | 3-axis with light passes | Low cutting force, less spring |
What we run
Services behind these resources
One shop, one inspection gate. Parts move between processes without a new supplier review.
01
5-Axis CNC Machining
16 simultaneous centers for complex housings and contoured surfaces in one setup.
02
Mill-Turn
16 centers that turn and mill a shaft without losing concentricity between operations.
03
Rapid Prototyping
From a single part to a fit-check batch before the hard tooling decision.
04
Sheet Metal Fabrication
Bent, punched and riveted brackets and enclosures alongside machined parts.
05
Surface Finishing
Anodizing, plating, powder coating, blasting and laser marking under one roof.
06
Inspection and Reporting
Raw material check, in-process monitoring, final inspection, reports on request.
Scope
Machining envelope and order range
Numbers you can plan a fixture and a budget around.
| Item | Range | Notes |
|---|---|---|
| Maximum part size | 4,000 mm | Long shafts and rails |
| Large travel | 4,000 × 400 × 150 mm | Gantry-class work |
| Medium travel | 750 × 1,150 × 550 mm | Typical housings |
| Tolerance | ±0.005 mm | ±0.0002 in |
| Order quantity | 1 to 10,000+ | No minimum order quantity |
| Quotation | Within 12 hours | Free DFM analysis included |
Why GreatLight
Six reasons these notes are worth reading
Each one is a number we can point at, not an adjective.
15Y
Machining since 2011
Fifteen years of production parts, not a pilot line spun up for a brochure.
127
CNC machines on site
16 five-axis, 12 four-axis, 27 three-axis and 16 mill-turn centers.
±0.005 mm
Held tolerance
Measured in process, not estimated from a first article alone.
99.99%
Qualification rate
Parts that pass the final gate on the first pass.
12 h
Quote and DFM
Feedback on wall thickness, radii and datum strategy before you commit.
3–5 d
Parts ship
Production can start within 24 hours of a released order.
7,600 m²Manufacturing space
3Wholly-owned plants
150Technicians
ISO 9001Plus IATF 16949, ISO 13485, ISO 27001
What this looks like in practice
Industries, part families and the numbers they demand
Aerospace brackets
Thin ribs, tight datums, full traceability on every lot.
- ±0.005 mm
- 100% inspection
- ISO 9001
EV and automotive housings
Bearing bores and sealing faces cut in one setup.
- IATF 16949
- Ra 0.8–1.6 μm
- 3–5 day ship
Medical device components
Small stainless parts, documented process, no finish contamination.
- ISO 13485
- 316L
- Reports on request
Robot structural parts
Splines, gear blanks and mounting plates held to the mating interface.
- 5-axis
- Mill-turn
- 10,000+ part runs
FAQs
Questions engineers ask before releasing an order
When should I choose wire EDM over milling?
Wire EDM wins when the part needs a sharp internal corner, is already hardened, or has a slot narrower than any available cutter.
Milling wins on three-dimensional contours, large pockets and cycle time. If the feature is prismatic and through-going, wire is usually faster and cleaner.
How does anodizing change a bearing bore?
Anodizing grows the surface by a few micrometres, and hardcoat grows it more. On a press-fit bore that growth can close the clearance entirely.
Tell us the mating part and the fit type. We mask or plug the bore and measure after coating, not before.
What makes Inconel harder to machine than stainless?
It keeps its strength at the temperature where carbide tools normally cut, so heat stays in the cutting edge instead of leaving with the chip.
That means lower surface speed, more tool changes and a rigid setup. We plan the tool path and the workholding before the first cut, not after.
Can you hold ±0.005 mm on a long shaft?
On features we can reach in one setup or index accurately, yes. The Ø400 mm rotary table and mill-turn centers exist for exactly that.
On a 4,000 mm part, the limit comes from thermal movement and support, not from the control. We will tell you which dimensions are realistic before quoting.
Is there a minimum order quantity?
No. We run from one prototype to 10,000+ part production runs.
The setup cost is the same either way, so a single part carries a higher unit price. That is arithmetic, not a policy.
How do you handle confidential drawings?
Uploads are secure and treated as confidential. We can sign an NDA before you send files.
ISO 27001:2022 is one of our certifications, which covers how that data is stored and accessed.
What does the free DFM analysis actually cover?
Wall thickness, corner radii, datum strategy, tolerances that will be hard to hold, and features that need a second setup.
It comes back with the quotation, within 12 hours. You can act on it or ignore it.
Which surface finish should I specify?
Ra 1.6–3.2 μm is fine for general machined surfaces. Sealing faces and bearing seats usually want Ra 0.8–1.6 μm or better.
Ra 0.2–0.8 μm is available where the function demands it, and it costs more because it takes longer.
Send the drawing, get the number
Upload a model or a 2D drawing and we return a quotation with DFM notes within 12 hours. No minimum order quantity, 100% inspection before shipment.
12-hour quote100% inspectionNo minimum order quantityNDA on request
