CNC Telephone Case Factory Insights: A Sourcing Guide

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  What matters most
• 2
  Machining against the other ways to make a phone case
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  Match the alloy to how the case will be used
• 4
  Wall thickness and internal clearance drive the quote
• 5
  Why five axes change the cost of a cnc telephone case
• 6
  Surface finish, tool marks and what the quote should say
• 7
  Certifications, inspection and the paperwork trail
• 8
  Lead time, MOQ and how to read a factory quote
• 9
  Pick the supplier before you finalize the drawing
• 10
  Seven steps from drawing to shipped case

The alloy decides weight, edge sharpness and how the anodized color reads in daylight. For most cnc telephone case projects we start with 6061-T6. It machines fast, anodizes to an even tone and holds a 0.8 mm wall without chatter on a well-supported fixture.

7075 gives a higher strength-to-weight ratio. That matters when the case has a thin frame around a large camera cutout. It costs more per kilogram and anodizes to a slightly darker, less uniform tone than 6061, so plan your color samples around it.

2024 machines to a sharper edge and takes a polished finish well, but corrosion resistance is lower and it is harder to source in thin plate. Use it for exposed trim pieces, not for a full case that will live in a pocket.

Titanium TC4 (Ti-6Al-4V) is the choice when scratch resistance and low weight both matter. Expect longer cycle times. Titanium cuts at roughly one third the feed rate of aluminum and dulls tools faster, so a titanium case costs two to three times an aluminum one at the same geometry.

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  6061-T6Default choice for anodized cases, 0.8 mm walls
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  7075Higher strength, darker anodize, higher cost
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  2024Sharp edges and polish, lower corrosion resistance
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  TC4 titaniumScratch resistant, slow to cut, highest cost

A phone case is mostly thin wall, and thin wall is where machined parts fail. Below 0.6 mm in aluminum, the part deflects under cutting force and you hear it in the finish. We hold 0.8 mm reliably on 6061 and 1.0 mm on titanium.

Internal clearance matters just as much. The case has to slide onto the phone without scratching it, and it has to grip without rattling. A common target is 0.15-0.25 mm total clearance around the body, with the tightest fit at the corners. Confirm the CAD model includes the phone's actual shell tolerance, not just the bare body.

Camera bumps and wireless charging coils are the two features that force a redesign. A metal back over a charging coil will block it. The usual fix is a machined pocket with a plastic or glass insert, and that insert adds a second part, a bonding step and a flatness requirement.

Antenna lines are another constraint. A fully closed metal case attenuates signal. Machined slots or a non-metallic band solve it, but each slot is another thin-wall feature to hold.

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  Minimum wall0.8 mm aluminum, 1.0 mm titanium
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  Fit clearance0.15-0.25 mm total around the phone body
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  ChargingMetal back blocks the coil, plan an insert

A cnc telephone case has openings on four or five faces: camera, buttons, port, speaker and often a side rail. On a 3-axis mill each face needs its own setup, and each setup costs a fixture, an operator load and a re-zero. Four setups also means four chances to stack up position error.

A simultaneous 5-axis machining center reaches those faces by rotating the part, so the number of setups drops to one or two. That improves the position tolerance between features and shortens the queue. It also lets the tool stay normal to a curved rail surface, which gives a more even finish on the sides.

The trade-off is programming time. Five-axis toolpaths take longer to prove out, and the first article usually needs one or two corrections. For a single prototype that overhead can dominate the price. For 200 pieces it disappears into the cycle time.

If your case has a flat back and simple through holes, a 3-axis machine is cheaper and just as good. Five axes pay off when features are angled, when the sides are curved, or when the surface finish must be uniform all the way around.

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  3-axisFlat geometry, 3-4 setups, lowest programming cost
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  5-axisAngled and curved features, 1-2 setups, tighter feature-to-feature position

Tool marks are the first thing a customer sees and the last thing a supplier wants to discuss. As-machined aluminum sits around Ra 1.6-3.2 μm and shows visible step-over lines under raking light. Bead blasting hides them. Brushing turns them into a directional grain. Polishing removes them entirely but softens edges.

Anodizing does not hide defects. It is a conversion coating roughly 5-25 μm thick depending on type, and it follows the surface underneath. A scratch before anodizing is a scratch after anodizing, only darker. Hardcoat anodizing is thicker and more wear resistant; it also shifts dimensions slightly, so call out any tight bore before the finish is applied.

Laser marking on an anodized case is clean and permanent. Minimum character height is 1.5 mm for a legible logo or serial. Below that the mark can fill in. If you need a two-color effect, plan a second anodize step or a masked etch.

Ask the quote to state the finish callout per surface, not one blanket note. The back of a case is usually cosmetic and the inside is usually functional. Separating them is the easiest way to save cost.

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  As-machinedRa 1.6-3.2 μm, visible step-over lines
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  Fine finishRa 0.2-0.8 μm after polishing
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  Laser marking1.5 mm minimum character height

Certificates are not a substitute for an inspection plan, but they tell you what systems already exist. GreatLight holds ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022. The last one matters for phone cases because your CAD files and brand artwork are the project.

Inspection should be named in the quote. We check raw material on receipt, monitor dimensions in process, and inspect 100% of parts before shipment. Reports go out on request. For a phone case the critical dimensions are the internal cavity, the camera opening, and the button cutout positions.

Ask what happens when a dimension drifts. A supplier that can show you in-process data and a documented reaction plan is easier to work with than one that only offers a final pass or fail.

Confidentiality is part of the same conversation. Uploads stay private, and an NDA is available on request before you send drawings.

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  Quality systemsISO 9001, IATF 16949, ISO 13485, ISO 27001
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  InspectionRaw material, in-process, 100% before shipment
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  ConfidentialityPrivate uploads, NDA on request

Quotation and DFM analysis come back within 12 hours. Production can start within 24 hours of approval, and parts ship in 3-5 days. Those windows assume the drawing is final and the material is in stock.

A machined case is a good fit for low and medium volume because no tooling is required. There is no minimum order quantity, so one prototype and a 10,000-part run go through the same first-article process. That is the main economic difference against injection molding, where the mold cost has to be spread over tens of thousands of parts.

When you compare quotes, compare the same scope. A low price often excludes the finish, the insert bonding or the first article report. Ask each supplier to list what is inside the number.

Also ask who machines the first article. A quote produced by a trading desk and cut by an unknown subcontractor is harder to control than one cut in the plant that quoted it.

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  Quote12 hours with free DFM analysis
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  StartProduction within 24 hours of approval
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  DeliveryParts ship in 3-5 days
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  VolumeNo MOQ, prototype to 10,000+ parts

Most cost is locked in before the first chip is cut. If the supplier reviews the CAD early, they can flag a 0.5 mm wall, a blocked antenna or an unreachable undercut while the model is still easy to change. That review is free and it usually saves more than it costs.

Bring the phone model, not just the case model. The fit depends on the phone's outer dimensions including any camera ring. Checking the assembly in 3D catches interference that a 2D section misses.

Decide early which surfaces are cosmetic and which are functional, and say so on the drawing. It sets the finishing route and the inspection plan at the same time.

Finally, ask for the sample center workflow. A supplier that treats a prototype as a real job, with the same inspection as production, gives you data you can trust before you commit to a run.

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  Early DFMFree review within 12 hours of upload
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  Send both modelsPhone and case, checked for interference
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  Label surfacesCosmetic against functional on the drawing