01
The material spec changed after quoting
A part quoted in 6061 aluminum gets switched to 7075 for strength. The original tool path and feeds no longer apply, so cycle time rises and the price you approved is gone.
Metal Alloy Guide & Service
CNC Machining Metals
We machine aluminum, stainless, titanium, steel, copper, brass and Inconel on 127 high-precision CNC machines. Quote and DFM analysis in 12 hours, tolerances to ±0.005 mm, and no minimum order quantity.
±0.005 mm tolerance127 CNC machinesNo minimum orderISO 9001 / IATF 1694912-hour quote
127High-precision CNC machines
16Simultaneous 5-axis centers
±0.005 mmAchievable tolerance
99.99%Qualification rate
Common Problems
When Metal Machining Goes Wrong
These are the failures we see most often when shops pick an alloy by habit instead of by application.
02
Hard alloys that eat the schedule
Inconel and titanium cut slowly. A shop that quoted them like mild steel will run out of spindle hours, and your delivery date slips by weeks while the machine sits at half speed.
03
Tolerance drift on thin walls
Aluminum and stainless parts with walls under 1 mm move during and after cutting. Without stress relief and in-process checks, the finished parts bow past the tolerance band.
04
Finish callouts that hide cost
Hardcoat anodizing or bead blasting adds steps, masking and handling. If those steps are not quoted up front, the invoice changes and the parts sit waiting at the finisher.
How We Machine Metals
Pick the Alloy, Then Match the Process
The right cutting strategy depends on the metal, not on a generic machining template.
Alloy Selection
Alloy selection drives every downstream decision
Aluminum 6061, 2024, 5052, 6082 and 7075 cut fast and hold tight tolerances, which makes them the default for housings and brackets. Stainless 303, 304, 316L and 17-4PH bring corrosion resistance but work-harden, so we slow the surface speed and take deeper passes to stay under the hardened layer.
Titanium TA2 and TC4 resist corrosion and heat but conduct heat poorly. Heat concentrates at the cutting edge, so we use high-pressure coolant and sharp carbide to keep the tool alive. Inconel and magnesium each need their own feeds, fixturing and chip control.
- 16061-T6 and 7075Good strength-to-weight, fast cycle times, clean anodized finish.
- 2303 vs 316L stainless303 machines easily; 316L is chosen for chloride and medical exposure.
- 3TC4 titaniumLight and strong, but needs coolant pressure and rigid setups.
Machining Strategy
One setup beats three setups
Every extra setup adds a datum error. On complex metal parts we use 16 simultaneous 5-axis centers and 16 mill-turn centers to cut five faces in one clamping. That keeps hole-to-hole position tight and removes the flip-and-reclamp step that causes mismatch.
For long parts we run travel up to 4,000 mm. Smaller work goes on 750 × 1,150 × 550 mm or 500 × 500 × 450 mm machines, with a Ø400 mm rotary table for parts that need angular features. All 127 machines are under one roof, so a job does not wait on outside capacity.
- 15-axis in one setupFewer datums, tighter position on multi-face parts.
- 2Mill-turnTurns and mills a shaft without a second operation.
- 34,000 mm travelLong rails and beams machined in a single pass.
Alloy Comparison
Metal Selection at a Glance
Use this as a starting filter. The final call depends on load, environment and finish.
| Metal | Typical Grades | Best For |
|---|---|---|
| Aluminum | 6061-T6, 7075, 6082 | Housings, brackets, heat sinks |
| Stainless | 303, 304, 316L, 17-4PH | Corrosion and medical parts |
| Titanium | TA2, TC4 (Ti-6Al-4V) | Aerospace, high strength-to-weight |
| Mild / alloy steel | 1018, 1045, 4140, 4340 | Shafts, gears, structural parts |
| Copper / brass | C110, C36000, beryllium copper | Conductors, RF and contacts |
| Inconel | Precipitation-hardening grades | Gas turbine and high-heat parts |
Metal CNC Services
What We Cut and How We Finish It
One supplier from raw bar to finished, inspected metal parts.
01
5-Axis CNC Machining
Sixteen simultaneous 5-axis centers cut contoured and multi-face metal parts in one setup, holding position without re-clamping.
02
CNC Milling & Turning
Milling, turning and mill-turn work on 27 three-axis, 12 four-axis and 16 mill-turn machines for round and prismatic parts.
03
Rapid Prototyping
Prototype metal parts from one piece, with DFM feedback before cutting so the design is machinable at volume.
04
Surface Finishing
Anodizing, plating, powder coating, black oxide, bead blasting and laser marking, managed in-house and at qualified finishers.
05
Sheet Metal & Die Casting
Enclosures and frames in sheet metal, plus die casting for aluminum ADC12 parts when machining alone is too slow.
06
Inspection & Reports
Raw material check, in-process monitoring and 100% final inspection, with dimensional reports on request before shipment.
Capability Range
Tolerances, Sizes and Volumes
Numbers you can design to.
| Parameter | Range | Notes |
|---|---|---|
| Tolerance | ±0.005 mm (±0.0002 in) | On critical features, checked in process |
| Surface finish | Ra 0.2–3.2 μm | Fine finishes need extra passes |
| Maximum part size | 4,000 mm | Long rails on large-travel machines |
| Rotary work | Ø400 mm table | Angular features on 5-axis |
| Order quantity | 1 to 10,000+ parts | Prototype and production on same line |
| Lead time | Ship in 3–5 days | After drawing and DFM sign-off |
Why GreatLight
Built for Metal, Not for Everything
We are a metal shop. The equipment and the inspection plan are set up around it.
15Y
Machining metals since 2011
Fifteen years on aluminum, stainless, steel, titanium and nickel alloys. Three wholly-owned plants, 150 technicians.
127
Machines in one place
16 five-axis, 12 four-axis, 27 three-axis and 16 mill-turn centers. No waiting on outside capacity.
±0.005
Tolerance we hold
±0.005 mm on critical features, with 100% inspection before shipment and reports when you need them.
12h
Quote and DFM in 12 hours
Send a drawing and get a price plus manufacturability notes. Production can start within 24 hours.
1pc
No minimum order
From a single prototype to a 10,000+ part run. The setup and inspection plan scales with the volume.
ISO
Audited quality systems
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022 cover quality, automotive, medical and data.
7,600 m²Manufacturing space
150Technicians on staff
99.99%Qualification rate
<2%Historical late-delivery rate
Industry Requirements
What Each Sector Demands, and What We Deliver
Aerospace
Titanium and Inconel brackets and housings where weight and heat resistance decide the alloy.
- TC4 / Inconel
- ±0.005 mm
- Full inspection report
Automotive & EV
Aluminum and alloy steel parts that must repeat across thousands of cycles without setup drift.
- 6061-T6 / 4140
- IATF 16949:2016
- 1 to 10,000+ parts
Medical Devices
316L and titanium components with clean surfaces and documented material traceability.
- 316L / TC4
- ISO 13485:2016
- Ra 0.2–0.8 μm
Industrial Machinery
Long steel rails and shafts machined in one pass up to 4,000 mm, then measured before shipment.
- 4,000 mm travel
- Steel 1045 / 4340
- 100% inspection
FAQs
Metal Machining Questions Engineers Ask
How do you choose between 6061 and 7075 aluminum?
6061-T6 is the default when you need machinability, weldability and a clean anodized finish. It holds tolerance well and cuts fast.
7075 is stronger but less weldable and costs more. Choose it when the part carries real load or needs high fatigue resistance. Send the drawing and we will flag the trade-off before quoting.
Can you machine titanium and Inconel to the same tolerance as aluminum?
Yes on critical features, but cycle time is much longer. Titanium and Inconel resist heat, so the cutting edge stays hot and tools wear faster.
We adjust feeds, use high-pressure coolant and take more finishing passes. That is why a titanium part costs more than the same geometry in aluminum.
What is the difference between 303 and 316L stainless for CNC parts?
303 contains sulfur for easy chip breaking, so it machines cleanly and is good for shafts, fittings and general hardware.
316L has molybdenum for chloride resistance and is the usual choice for medical, food and marine exposure. It work-hardens, so the cutting strategy changes.
How small can features get in metal parts?
It depends on depth. A Ø1 mm hole is routine in aluminum at shallow depth; in stainless or titanium the same hole needs a pilot and a rigid setup.
Laser marking characters should be at least 1.5 mm tall to stay readable after finishing. Send the drawing and we will tell you which features need a note.
Which surface finishes are available on machined metals?
Anodizing in clear, color, hardcoat or conductive types for aluminum. Electroless nickel, zinc, silver and gold plating for conductivity and wear.
Powder coating and black oxide for appearance and corrosion. Bead blasting, tumbling, brushing and polishing control the surface before those steps.
Do you take one-off metal prototypes?
Yes. There is no minimum order quantity, so a single prototype and a 10,000+ part run both fit the same process.
The difference is the setup and inspection plan. For one part we check the drawing and cut; for volume we add fixtures, in-process gauging and sampling.
How fast can metal parts ship?
Quotation and DFM analysis come back within 12 hours. Production can start within 24 hours after you approve the drawing.
Typical parts ship in 3–5 days. Hard alloys and heavy finishing add time, and we will state that in the quote rather than after the fact.
How do you protect drawings and material data?
Uploads are kept secure and confidential. An NDA is available on request before you send files.
Our ISO 27001:2022 certification covers information security, and customer drawings are not shared outside the project team.
Send a Metal Part Drawing, Get a Price
Upload your file and we will return a quote with DFM notes, alloy suggestions and a finish plan within 12 hours.
12-hour quote100% inspectionNo minimum orderNDA on request
