CNC Turning Services

We machine rotational parts with the locating, mating and fastening features your assembly needs, from a simple pin to a bored, threaded fitting.

Representative geometry illustrations.

Locating diameters, shoulders, retaining grooves and end features for alignment and mounting. Short shafts and locating pins share the same need for clear mating dimensions and reference surfaces.

Through-bores, stepped outside diameters and flanged ends for guiding, spacing or locating another component. The bore, outside diameter and length work together to establish the required fit.

Axial spacers, locating collars, flanges and bored hubs for positioning components. Roller and pulley profiles can combine concentric diameters and grooves with drawing-defined faces and secondary features.

Fittings, connectors and valve or pump component geometries with internal or external threads, axial passages and accessible side features. Knobs, dials and small cylindrical housings add adjustment or enclosure interfaces. Pressure, sealing and complete enclosure requirements are specified for the application.

Our turning team machines the cylindrical body and its mating features in-house, then adds accessible side features through mill-turn or secondary milling.

Outside and inside diameters, axial drilling and boring, facing, shoulders, grooves, and internal or external threads.

Rotational parts with side holes, slots, flats or keyways, where tool access and the selected setup permit the feature combination.

Diameter and length limits are assessed independently. The smallest diameter cannot be combined with the greatest length as one stated capability.

For components needing several processes, explore our CNC machining services.

For this 100-piece 316L sleeve order, we machined two mating diameters and a fine functional surface before passivation and final inspection.

Turning and finish fitting established the mating surfaces. Controlled deburring addressed the edges before passivation; the agreed diameters, length and surface requirements remained separate inspection items.

Machining and process inspection took 12 working days, followed by 3 working days for passivation and final inspection: 15 working days in total for this project. Your quotation sets the schedule for your own material, geometry and finish.

316L sleeve project — illustration.

Representative geometry illustrations; each shows a different material and feature combination.

Aluminum stepped shaft: A locating shoulder and retaining groove define the shaft’s axial position.

C36000 brass fitting: An axial passage and external thread combine with wrench flats for assembly.

Stainless steel flanged sleeve: A bore and flange face create distinct radial and axial mating interfaces.

POM spacer: A thick wall and broad locating face provide a supported plastic geometry for fit evaluation.

C11000 copper contact: Stepped contact surfaces and a cross-hole bring burr control into the connection detail.

Steel grooved collar: A concentric bore and groove combine with a side feature for locating or retention.

We source machining stock for your specified grade, material state and part geometry, including required brands, standards and material documents.

Material examples — illustrations.

We supply machined parts with the agreed surface finish and coordinate specialist treatments through selected partners. The functional surfaces and cosmetic faces can require different treatment.

Final-fit acceptance: Critical diameters and threads are accepted in the agreed after-treatment condition, with protected surfaces and reinspection dimensions identified before order release.

Surface finish examples — illustrations.

Parts for equipment development, assembly fixtures and mechanical interfaces, with material, documentation and acceptance requirements matched to their use.

Application contexts — illustrations.

Short shafts, locating pins, sleeves and spacers for fixtures, end-of-arm tooling and mounting interfaces. Mating dimensions, weight and stiffness requirements establish the part specification and baseline for the next approved batch.

Adjustment knobs, connector details, sleeves and locating spacers for measurement and test equipment. Assembly interfaces, appearance and electrical contact surfaces determine the finish and its effect on fit.

Non-implant fixture sleeves, locating spacers and prototype mechanical components with specified traceability and documents. Patient contact, special cleanliness and final-use qualifications require project-specific review.

Test-bench shafts, pins, sleeves and connection details for prototypes and development fixtures. Validation quantities and controlled drawing revisions guide the order; safety-critical serial production requires separate qualification.

Short prototype shafts, sleeves and spacers for assembly or test fixtures with specified material and documents. Flight-critical parts and customer approvals are evaluated separately.

Prototype knobs, threaded rotational fittings and small mechanical interfaces. Appearance, color, texture and fit matter alongside any difference between prototype stock and the intended production material.

Shafts, sleeves, fittings and connectors for defined mechanical assemblies. Media, mating fit, wear surfaces and acceptance methods govern requirements; pressure, leakage and service-life performance need application-specific validation.

We quote the dimensions and surfaces that govern your assembly against the material, accessible geometry, datums and inspection method.

General tolerances for unmarked dimensions are agreed before ordering. A general-tolerance standard does not assign one value to every nominal size.

Clear feature relationships let us machine and inspect the part you intend to assemble.

Allow sufficient stock and gripping length. Slender sections need support matched to their material and geometry. State the OD and ID limits and identify datums for runout; “tight fit” alone does not define an acceptance requirement.

Deep bores need tool reach and chip clearance. Local metal walls can be assessed from 0.8 mm, and plastic walls from 1.5 mm, where small structures can be supported. Shallow holes can be assessed from Ø0.5 mm; material, depth and breakthrough length determine feasibility.

Internal and external threads are assessed from M2. State pitch, tolerance class, effective engagement, blind-hole clearance and gauging requirements. Groove widths, tool nose radii and shoulder relief must leave access for the cutting tool and the mating component.

Identify chamfers, edge breaks and burr-sensitive faces, including cross-hole breakouts inside a bore. Keep identification clear of functional fits. Part marking is available as an order option.

There is no universal length-to-diameter limit: the stock, support, tool access and required finish determine the suitable setup.

We carry the approved drawing, material and inspection requirements from the sample into subsequent orders.

CNC enquiries start from one piece, with common prototype orders of 5–20 pieces. Simple stocked aluminum or POM parts in quantities of 1–10, with normal tolerances and deburring, typically take 5–7 working days. More complex work, often 5–20 pieces, typically takes 8–12 working days; special material procurement and heat treatment are scheduled separately.

Small batches commonly run 20–500 pieces. Approve the drawing revision and agreed sample or first piece before releasing production. The quotation defines the machining hours, inspection deliverables and schedule for that batch.

Repeat orders commonly run 100–5,000 pieces, subject to machining hours and scheduling. Approved repeat batches typically take 12–20 working days, with the approved revision, material and inspection requirements carried forward.

Quantity ranges overlap; they are examples of purchasing stages, not fixed minimum-order classes. Setup or material minimums can still affect individual projects.

Lead times start after requirements, order conditions and material are confirmed. Common specialist finishing adds 3–5 working days; customer approval and shipping are separate.

Prototype and batch part examples — illustrations.

A lathe rotates the workpiece while controlled cutting tools produce the required profile around its axis.

Turning and axial boring — illustration.

1. Rough and finish turning: Remove stock, face the ends and form outside diameters, shoulders and grooves.

2. Bores and threads: Drill or bore axial features and cut specified internal or external threads.

3. Side features: Use mill-turn or secondary milling for accessible holes, slots, flats and keyways.

4. Finish and check: Deburr, complete the agreed surface treatment and inspect the specified features.

A rotational body with diameters sharing a central axis favors turning. Prismatic parts, pockets and faces in multiple directions favor CNC milling. Some parts need both operations.

First-piece, process and final checks follow the agreed drawing revision and critical features. Our resources include one CMM, two vision measuring systems, one roughness tester and suitable hand gauges.

Instrument choice depends on range, access, probe, temperature and measurement uncertainty. Every part does not need every instrument; a selected ±0.005 mm feature requires a suitable acceptance method of its own.

Key-dimension reports, available source material documents, a Certificate of Conformity and formal First Article Inspection can be agreed with the quotation. Routine first-piece checks and a formal FAI package are different deliverables. Full dimensional or 100% inspection is a separate scope.

Partner finishes are checked on return against the agreed treatment and applicable critical dimensions. Revision, material and inspection requirements remain associated with repeat orders.

Explore our quality and inspection arrangements.

Your cylindrical body and accessible secondary features are machined by one in-house team responsible for the finished machined part.

Receive your machined component with specialist treatments coordinated through one project contact. Selected partners receive the material, finish and protected-fit requirements; treated parts are checked on return.

Get a quotation that addresses tool access, critical fits and open drawing questions through direct discussion with the team responsible for machining your part.

Reorder against the approved drawing revision, material and inspection requirements. Our team resolves drawing changes before releasing the next batch.

Enough to start: Send a drawing, CAD file, sample or useful part description, plus quantity or development stage if known. We can identify the remaining questions with you.

Helpful for quotation: STEP or IGES plus a revision-marked PDF drawing; exact material grade and state; quantity levels; critical dimensions, tolerances, ID and OD fits, datums and runout; threads and burr limits; surface finish and masking; application or operating conditions; inspection documents; packing needs; delivery country and target date.

Our first human reply is within one working day. Straightforward CNC requests with complete requirements are usually quoted within one working day; complex requests generally need 2–3 working days. The first reply and the formal quotation are separate steps.

For an NDA or an open project question, contact us or email Great Machining.