What tolerances can CNC machining hold?

A standard CNC process holds about ±0.005 in (0.13 mm), and ±0.001 in (0.025 mm) with added effort. Tighter, aerospace-grade tolerances are achievable at shops equipped for them. Applying tight tolerances only where a feature needs them keeps cost down.

What materials can be CNC machined?

Metals including aluminum, stainless steel, steel alloys, titanium, brass, copper, bronze, and Inconel; engineering plastics such as Delrin, nylon, PEEK, PTFE, ABS, PVC, and polycarbonate; and composites like G10/FR4.

What is the difference between 3-, 4-, and 5-axis machining?

3-axis machining suits prismatic parts and simple geometries; 4- and 5-axis add rotation to reach complex geometries, undercuts, and contoured surfaces in fewer setups, which improves accuracy and reduces repositioning.

What is the difference between CNC milling and turning?

Milling cuts a fixed workpiece with a rotating tool and suits prismatic and complex parts; turning rotates the workpiece against a fixed tool and suits cylindrical parts, shafts, and threaded features. Mill-turn machines combine both.

How do I get a CNC part made through Trustbridge?

Through Trustbridge design services: we help get your part production-ready and carry it into the network to be made. If you run a CNC shop, you can join the network by application. Direct self-serve sourcing is not open yet — join the waitlist.

What files are needed for a CNC part?

A 3D model in STEP, IGES, SLDPRT, or STL, plus a 2D drawing (PDF or DXF) that calls out tolerances, finishes, and threads.

Custom CNC Machining Services | 5-Axis Milling & Turning

Precision CNC Machining Services For Prototypes and Production

The network covers the full range of CNC milling and turning — 3-, 4-, and 5-axis — across metals, engineering plastics, and composites. This page isn't a buyer portal; it's a look at the CNC work the network is built to handle, and the capabilities our design team relies on when a part is headed for machining.

Technical Specifications & Tolerances

Our partners routinely achieve industry-standard and tight-tolerance CNC specs:

Feature	Standard Spec	Precision Spec
Dimensional Tolerance	±0.005" (0.127mm)	±0.001" (0.025mm)
Surface Finish	As-Milled (125 Ra)	Smoothed (32 Ra) / Polished (16 Ra)
Max Part Size	20" x 20" x 12"	Custom Large Format Available
Threads & Holes	Standard UNC/Metric	Helicoil Inserts / Custom Threads

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Material Capabilities for CNC

Our CNC machining network offers a broad range of material capabilities:

Metals
- Aluminum: 6061-T6, 7075-T6, 2024 (Best for aerospace & prototypes).
- Stainless Steel: 303, 304, 316, 17-4 PH (Corrosion resistant).
- Alloy Steel: 1018, 4140, A36 (High strength industrial parts).
- Engineering Plastics: Delrin (Acetal), PEEK, Nylon 6/6, Polycarbonate.
- Titanium: Grade 5 (Ti-6Al-4V) for medical/aerospace applications.
Plastics
- Acetal (Delrin)
- Nylon
- PEEK
- PTFE (Teflon)
- ABS, PVC, Polycarbonate
Others
- Carbon-fiber-reinforced composites
- G10, FR4
- UHMW, HDPE

Need help selecting the right material? Our engineers will guide you based on your part’s performance, finish, and cost requirements.

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CNC Technologies & Equipment

We support a wide range of CNC machining technologies:

3-Axis Milling – Ideal for simple part geometries
4-Axis and 5-Axis Milling – Complex geometries, tight tolerances, high-speed
CNC Turning / Lathe Work – For cylindrical parts and concentric operations
Mill-Turn Capabilities – Combined setups for high efficiency
Swiss Screw Machining – Ideal for small, high-precision parts
EDM (Electrical Discharge Machining) – For hard metals and intricate internal cuts

Many of our partners run high-end machines from Haas, Mazak, DMG Mori, Okuma, and more.

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Industries We Serve

Our CNC machining network serves companies in:

Aerospace & Defense
Automotive & EV
Medical Devices & Dental
Industrial Equipment
Robotics & Automation
Consumer Electronics
Oil & Gas

We understand the engineering and regulatory nuances unique to each industry.

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450+ CNC machining shops across North America, Europe, and Asia

Vetted CNC Machine Shop Network

Access a global network of ISO 9001:2015 certified and ITAR registered machine shops. We match your project to the right facility—whether you need a local USA machine shop for rapid turnaround or an international partner for low-cost volume production.

Trustbridge gives you instant access to:

450+ CNC machining shops across North America, Europe, and Asia
60% of suppliers ISO 9001 certified; many with AS9100 and ITAR registration
Global reach, local speed — with U.S.-based suppliers in 20+ cities
10+ years of average shop experience
Performance-tracked partners based on quality, responsiveness, and on-time delivery

We do the supplier due diligence so you don’t have to.

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Case Study Highlight

Customer: Industrial Automation OEM
Service: CNC Milling & Turning
Challenge: 150-part prototype batch in 7 unique SKUs; tight 0.001” tolerances
Solution: Matched to a U.S.-based 5-axis machine shop with proven track record
Result: All parts delivered in 5 business days; passed QC with zero deviations
“Trustbridge delivered exactly what we needed — precision, speed, and engineering oversight. Our go-to partner for CNC projects.”
— Lead Mechanical Engineer, Industrial Automation Company

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Frequently Asked Questions

What files do you accept?

We accept STEP, IGES, SLDPRT, STL, and DXF files, along with 2D drawings (PDF) for tolerances and finishes.

What’s your standard turnaround time?

Typically 3–5 business days for smaller orders, with expedited options available in major metro areas.

Can I request a custom surface finish?

Yes — we support bead blasting, anodizing, powder coating, polishing, and more.

Are my designs secure?

Yes — Work is done under NDA by default. All files shared via Trustbridge are encrypted. While all suppliers have been vetted for reasonable file security protocols, engage with them to confirm.

Why Work With Trustbridge?

One Match, Not a Bidding Pool
Inbound work is routed to the shop whose capabilities fit it — one qualified introduction, never a scattershot across a pool. No trial-and-error, no race to the lowest bid.

Direct, Not Brokered
The manufacturer and the customer work directly. Trustbridge makes the introduction and stays involved only where it helps — the maker is never buried behind a broker, and the relationship, along with everything that comes after it, stays with the shop.

Vetted, Capability-Fit Work
From high-spec aerospace shops to agile job shops, work is routed to a manufacturer whose quality level and capabilities actually fit the job — not a blind handoff.

A Vetted Network Across Regions
The network spans vetted, performance-tracked shops across regions, so work can be routed to a manufacturer that fits the job's process, materials, and location.

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Custom CNC Machining Services: Milling & Turning

Precision CNC Machining Services For Prototypes and Production

Technical Specifications & Tolerances

Material Capabilities for CNC

Material Capabilities for CNC

CNC Technologies & Equipment

Industries We Serve

Industries We Serve

Vetted CNC Machine Shop Network

Case Study Highlight