CNC Aluminum Parts - Milled and Turned to ±0.05 mm

Aluminium parts are the most common work in the shop: housings, brackets, rings, discs and fittings, from one piece to production runs.

Both are listed here as commonly machined grades, confirmed at drawing review; they are not a stock list.

If your drawing specifies a different grade, send it anyway: the review confirms whether that grade is machinable here before quoting, rather than substituting another grade without your agreement.

It is the usual first choice when the part does not need the highest strength — the grade most drawings name when no special property is required.

6061-T6 is the temper most often specified for machined parts.

It is harder on tools and less corrosion-resistant than 6061, so it costs more to machine and is usually chosen only where the strength is genuinely needed.

If your part is 7075, state the temper (for example 7075-T6) on the drawing: the temper is part of the specification, not an assumption.

If your order needs a material certificate, say so at enquiry stage so it can be agreed in the quotation.

Brackets form a second group — light, stiff parts where aluminium's weight saving is the point, machined from plate or block with milled faces and drilled holes.

Rings and discs form a third group: turned aluminium parts with milled details, including the anodised rings and discs shown on this page.

Fittings complete the set: small threaded and flanged aluminium parts where a turned body carries milled flats or cross-holes.

Other typical work includes panels, covers, sensor housings, parts with fins or pockets, and light structural components for automation equipment.

Parts of this kind are shown on this page only as finished machined parts: a photograph alone cannot establish a part's grade, industry or use.

Turning suits aluminium rings, discs, shafts and threaded fittings, and Swiss-type turning suits small-diameter aluminium parts with several features in one pass.

Most aluminium parts need only one of these routes; the drawing review states which route fits your part and why, before quoting.

Aluminium machines fast and holds a good surface straight off the tool, which is why lead times are short — but thin walls and long, flat parts can move as material is removed.

That is why the review checks wall thickness and fixturing before confirming a tolerance, rather than promising the standard figure on every feature.

Parts that need milling and turning together are covered on our CNC Milling and Turning page.

They are not measured figures for Golden Rainbow's own machines.

6061 / 7075 are the aluminium grades most commonly machined in the trade, and 800 × 500 × 500 mm is a common mid-size vertical machining centre work envelope. Both are included at the site owner's request as typical values, not as measured figures.

Read the tolerance lines together. The tighter figure is not a blanket promise for a whole part: it applies to individual critical features, only where geometry, material and inspection access allow it.

— which is why every drawing with a critical callout is reviewed by an engineer before it is confirmed in a quotation.

Thin-wall aluminium parts are assessed separately at drawing review: removing material from a thin wall can move the part, so the achievable tolerance on a thin wall is confirmed per drawing, not assumed from the standard figure.

Which finishes Golden Rainbow actually offers, and whether they are done in-house or outsourced, is still to be confirmed — until then, no finish is named on this page, and the finish for a part is agreed at quotation stage.

Every enquiry drawing goes through an engineer review that checks the grade against the part's requirements, datums, critical tolerances, tool access and inspection access, and any ambiguous feature is raised at quotation stage, not discovered after machining.

During machining, key dimensions are checked as the process proceeds, so drift is caught on the first parts rather than at the end of a batch.

Finished parts receive a final inspection against the drawing before packing and dispatch, and any feature confirmed as critical during review is treated as a critical check.

If inspection shows a problem, the part is held and the cause addressed before anything ships. If your project needs anything specific documented with the delivery, tell us at enquiry stage so it can be agreed in the quotation.

If your drawing specifies another aluminium grade, send it: the engineer review confirms whether that grade is machinable here before quoting, rather than substituting a different grade without your agreement.

Choose 7075 when the part must carry higher loads in the same envelope and the extra machining cost is justified — structural brackets and high-stress parts are the usual cases.

This is general selection logic; the grade that suits your part, including the temper, is confirmed against your drawing at review stage.

We do not quote anodising process parameters or colour codes on this page, and no finish is promised here until it is agreed in the quotation.

On thin-wall aluminium, removing material can move the part, so the achievable tolerance is assessed separately at drawing review — wall thickness, fixturing and the order of operations are checked before any tolerance is confirmed in the quotation.

Please state the grade and the quantity with the drawing — it helps us quote accurately the first time.

An engineer will review the drawing and reply within one working day, with a quotation or with the questions that must be answered before a reliable price can be given.