This is an engineering reference for the aluminum CNC machining we run in-house — milling, turning, finishing, and inspection. Use it to judge whether we can hold your part's tolerances, features, and finish before you send an RFQ.
We machine 6061, 7075, 2024, 5052, and MIC-6 aluminum from prototype through low-volume production, with DFM feedback and an engineering review of your drawings within one business day.
Every process below is chosen for a reason. This is how we decide which one fits your aluminum part, its features, and its tolerance requirements.
Milling on X, Y, and Z for prismatic aluminum parts — plates, brackets, covers, and housings with features approached from the top and sides.
Typically selected forFlat-faced, accessible geometry where features sit on one or two planes. The most cost-effective route for the majority of aluminum parts.
Adds an indexing or continuous rotary axis so the part turns to present new faces without a manual re-fixture.
Typically selected forRadial features, cross-drilling around a bore, and multi-face parts where a fourth axis removes setups and protects feature-to-feature position.
Positions the tool at compound angles (3+2) or moves five axes together for contoured surfaces and deep, angled reach with short, rigid tools.
Typically selected forComplex contours, angled bosses, and multi-face parts that would otherwise need several setups — improving accuracy and shortening lead time.
Turning of round aluminum stock for concentric features, with live tooling for cross-holes, flats, and slots on the same setup.
Typically selected forShafts, bushings, spacers, standoffs, and threaded parts where concentricity, roundness, and turned diameters are the driving requirement.
Tapping, reaming, boring, cross-drilling, chamfering, engraving, and controlled deburring after the primary milling or turning operation.
Typically selected forPrecision holes, threaded features, and edge conditions that are best cut or finished as a dedicated, repeatable operation.
Installation of threaded inserts, dowel pins, and hardware, plus light sub-assembly, kitting, and pre-fit checks before parts ship.
Typically selected forParts that arrive ready to build — where press-fit inserts, helicoils, or mated components reduce work on your line.
A quick engineering summary of what we support. Values marked to be confirmed are left for verified factory specifications so nothing here is invented.
| Capability | Our support |
|---|---|
| CNC milling | 3-axis, 4-axis, and 5-axis aluminum milling |
| CNC turning | Shafts, bushings, spacers, standoffs, and threaded turned parts with live tooling |
| Maximum part size | To be confirmed Milling envelope and turning swing × length |
| Minimum feature size | To be confirmed Smallest cutter diameter and slot / wall capability |
| Supported threads | Metric, UNC, UNF, NPT, and custom threads — cut, formed, or thread-milled |
| Surface roughness | To be confirmed Achievable Ra by process (as-machined and finished) |
| Typical tolerance | General ±0.05 mm; fine aluminum features to ±0.005 mm (geometry-dependent review) |
| Inspection equipment | CMM, height gauge, micrometer, thread gauges, and calipers |
| Aluminum alloys | 6061, 7075, 2024, 5052, MIC-6, and customer-specified grades |
| Documentation | Material certificates, FAI reports, and dimensional reports on request |
Tolerances and finishes depend on geometry, aluminum alloy, and inspection method — we flag risk before machining starts. See the aluminum grade machining guides and surface finishes hub for feature-level detail.
Aluminum is fast to cut but unforgiving to control. These are the problems that separate a part that measures in from one that warps, burrs, or drifts — and how experienced machining keeps yours reliable.
Walls below roughly 1 mm deflect under cutting and clamping forces, causing chatter, taper, and dimensional drift — worsened by aluminum's low stiffness.
Wall-to-height ratio, tool engagement, climb milling, a finishing allowance, and low-stress fixturing all set the achievable thickness.
We sequence roughing and finishing, leave adaptive stock, and take light finishing passes with sharp tooling to hold flat, parallel walls without deformation.
Deep pockets force long tool overhang, which reduces rigidity and invites deflection, a poor floor finish, and chip-evacuation problems.
Depth-to-diameter ratio, corner radii sized for the largest usable tool, ramping strategy, and coolant or air blast for chip clearing.
We select the shortest viable tool stack-up, step down in controlled passes, and open generous corner radii in DFM to keep floors flat and walls straight.
Rolled aluminum plate carries residual stress; removing material unbalances it and the part bows after machining.
Stock choice (cast tooling plate such as MIC-6 vs. rolled), stress relief, symmetric material removal, and vacuum or low-clamp fixturing.
We recommend pre-stabilized plate, machine both faces to balance stress, and re-check flatness before final passes to hold tight datums.
Heat, clamping load, and unbalanced stock removal lock stress into the part, which releases as warp once it leaves the fixture.
Separating roughing and finishing, rest periods, reduced clamping pressure, and coolant strategy to limit thermal gradients.
We rough with stock left on, relieve clamps, let the part settle, then finish — keeping long, thin aluminum parts within tolerance.
Soft, ductile aluminum raises burrs at hole entries, thread crests, and intersecting features, affecting fit, sealing, and cosmetics.
Tap selection, cut tap vs. thread mill, entry chamfers and countersinks, and deburr access for cross-holes.
We add entry chamfers, thread-mill where finish matters, and apply controlled manual and tumbling deburr so threads gauge cleanly and edges stay safe.
Aluminum scratches and dents easily; handling marks, fixture witness, and tool lines show badly on parts that will be anodized or left visible.
Identifying A-surfaces, grain direction, fixturing off non-cosmetic faces, and protected handling between operations.
We map cosmetic surfaces at quoting, protect them through machining and finishing, and route contact points away from visible faces.
Bores, bearing seats, and mating interfaces at ±0.01 mm and tighter demand thermal, tool-wear, and metrology control that general tolerances do not.
Which dimensions are truly critical, reaming or boring vs. milling, temperature-stable finishing, and in-process gauging.
We isolate critical features, finish them as dedicated operations, and verify with calibrated gauges and CMM before release.
True-position callouts on hole patterns stack fixturing, spindle, and datum error; loose control causes assembly misalignment.
Datum scheme, single-setup drilling where possible, spot-drilling, and rigid tapping to hold position and perpendicularity.
We work from clear datums, drill patterns in one setup, and inspect true position so bolt patterns and dowels align first time.
Large plates are hard to hold flat, prone to stress-induced movement, and challenge machine travel and repeatability across the surface.
Bed support, multi-zone clamping, part envelope vs. machine travel, and flatness measured across the full field.
We plan support and clamping to keep large plates stable, machine in balanced passes, and verify flatness across the whole part.
Compound angles, contoured surfaces, and features on many faces are setup-heavy on 3-axis alone, and multiple setups introduce stack-up error.
3+2 positioning vs. simultaneous 5-axis, tool reach and collision clearance, and consolidating setups to protect accuracy.
We use 4- and 5-axis work to reach features in fewer setups, improving accuracy between faces and shortening lead time on complex parts.
Finish is part of the specification, not an afterthought. Here is what each option delivers on aluminum — and the concerns that decide whether it looks and fits right.
Adds corrosion and wear resistance while keeping a natural metallic look — a durable default for most aluminum parts.
Uniform matte-to-satin black for enclosures, optical parts, and cosmetic hardware where dye consistency matters.
A thick, dense, wear-resistant layer for sliding surfaces and harsh environments — grows part dimensions, so it is planned in.
A uniform matte cosmetic texture that hides tool marks; also a common, even pre-anodize preparation.
Coarser media for a heavier texture, controlled reflectivity, or surface cleaning ahead of finishing.
A directional satin grain for a premium look on visible faces, applied along a defined grain direction.
Permanent part numbers, logos, and data-matrix codes with no measurable effect on part dimensions.
Read the finish guides for clear anodized aluminum, black anodized aluminum, hardcoat anodized aluminum, bead blasted aluminum, chem film (Alodine), and aluminum laser marking — or compare them all in the aluminum surface finishes hub.
Dye lot, alloy, and bath conditions shift shade. We batch parts together and work to a reference sample so color stays consistent across an order.
Type II and Type III build differently and grow dimensions. We account for film build on tight features, threads, and press fits before finishing.
Define A-surfaces and acceptance criteria so cosmetic targets are unambiguous rather than judged part by part.
Threads and reamed bores are masked or specified so film build does not bind fits or change gauge results.
Parts hang on racks and leave small unanodized witness marks. We agree rack locations on non-critical areas up front.
Even color needs uniform preparation — machining lines telegraph through thin films, so we blast or etch to a consistent base.
Inspection is scaled to your requirements — from a quick dimensional check to a full FAI with a ballooned report. Tell us what the part demands and we match the method.
A full dimensional record of the first part against the drawing, used to sign off a new part or a new revision before production.
Coordinate measuring for true position, profile, flatness, and tight bores where hand tools cannot resolve the tolerance.
Step, height, and datum-referenced dimensions checked on a surface plate for prismatic aluminum parts.
Precise outside diameters, thicknesses, and turned features measured to close tolerance.
Go/no-go plug and ring gauges confirm tapped and turned threads meet class of fit.
Ra verification and cosmetic review against the specified finish, texture, and appearance.
Mill certificates trace the aluminum alloy and temper back to the supplied stock when the order requires it.
Ballooned drawings with recorded measurements for critical features and customer-defined checkpoints.
Not sure what level of inspection your part needs? Our quality assurance approach explains how FAI, in-process checks, and documentation are selected against your drawing.
Alloy choice drives strength, finish, corrosion resistance, and cost. These are the grades we machine most, with a full engineering guide behind each one.
| Alloy | Why engineers specify it | Typically selected for |
|---|---|---|
| 6061 | The all-round workhorse — good strength, excellent machinability, weldable, and anodizes cleanly. | Brackets, housings, plates, and general structural and enclosure parts. |
| 7075 | High strength-to-weight, approaching some steels, with good fatigue resistance. | Aerospace tooling, high-load structural parts, and stressed brackets. |
| 2024 | High strength and fatigue resistance where its lower corrosion resistance is managed with a coating. | Aircraft structure, fittings, and fatigue-critical components. |
| 5052 | Excellent corrosion resistance and formability; a marine and sheet-friendly grade. | Enclosures, panels, and parts exposed to moisture or chemicals. |
| MIC-6 | Stress-relieved cast tooling plate that stays flat and stable through machining. | Base plates, jigs, fixtures, and precision flat references. |
Full machining guides: 6061 aluminum CNC machining, 7075 aluminum CNC machining, 2024 aluminum CNC machining, 5052 aluminum CNC machining, and MIC-6 aluminum plate machining.
A few minutes on the drawing package saves a round of DFM questions and gets you an accurate quote faster. This is what helps us most.
Go deeper on the products we make, the alloys and finishes we work with, and the industries we support.
See the aluminum parts we machine — housings, brackets, shafts, manifolds, fixtures, and custom components.
Open aluminum cnc machining products Aluminum materials hubCompare 6061, 7075, 2024, 5052, and MIC-6 machining guides to select the right alloy for your part.
Open aluminum materials hub Aluminum surface finishes hubAnodizing, blasting, brushing, and laser marking compared, with the engineering trade-offs for each.
Open aluminum surface finishes hub Industries we serveHow our aluminum CNC machining supports robotics, medical, aerospace, electronics, and industrial programs.
Open industries we serveJump straight to a product: aluminum housings & enclosures, brackets & mounts, shafts & bushings, manifold blocks, fixtures & tooling, or custom aluminum parts.
Or see the work by industry: robotics, automation equipment, medical devices, aerospace tooling, electronics housings, and industrial equipment.
Featured aluminum CNC machining case studies with specifications, engineering challenges, inspection, and finishing.
A pocketed 6061-T6 instrument enclosure with connector cutouts, standoff bosses, and conductive grounding pads, machined and finished for a low-volume electronics build.
A sealed 6061-T6 control module enclosure with a machined O-ring gland, threaded service bosses, and a bead-blasted black anodize finish for vibration- and coolant-exposed environments.
A 7075-T6 structural arm bracket with lightweighting pockets, precise bearing bores, and hardcoat anodize, machined for stiffness-to-weight in a robotic joint.
Browse the full engineering portfolio in the aluminum CNC machining case studies hub.
Upload your CAD and drawings, or message an engineer directly. We review manufacturability, flag tolerance and finish risk, and reply with next steps within one business day.
