Custom CNC Turning & Milling for Brass Medical Device Parts

This brass component is only about 18 × 5 mm, but several machined features are concentrated within that small envelope.

Produced for medical equipment and shipped to a customer in the United States, the part combines a slender shaft with multiple stepped diameters, shoulders and raised sections along its length. Additional non-rotational features require milling after the main turning work.

The customer required approximately 8,000 pieces, with selected critical dimensions specified at around ±0.01 mm.

For a part like this, the job is not simply about machining something small. The real work is establishing a repeatable process that can hold the drawing requirements across thousands of components.

Project Overview

More Than a Simple Turned Pin

Most of the component is rotational, which makes precision CNC turning the starting point.

The shaft changes diameter several times over a length of only 18 mm. These changes create closely spaced shoulders and larger sections that need to remain correctly positioned along the part.

Turning establishes this basic geometry.

The additional non-round features are then completed by milling. Instead of treating the two processes independently, the machining sequence is planned around the finished component and the references defined on the customer's drawing.

This is where CNC turning and milling works well: most of the material is handled efficiently on the lathe, while milling is used only where the geometry requires it.

On a Small Part, Feature Relationships Matter

An 18 mm overall length does not leave much distance between features.

A shoulder position, shaft diameter or secondary machined feature may be individually correct, but the component still has to match the dimensional relationships shown on the drawing.

Several critical dimensions on this project are specified at approximately ±0.01 mm.

We focus on those specific callouts rather than describing the whole part as a ±0.01 mm component. Other dimensions are produced and inspected according to their own drawing tolerances.

This is particularly important when quoting custom CNC turned parts. Part size alone says very little about machining difficulty; feature density, tolerance and the relationship between operations usually tell us much more.

Building a Process for 8,000 Pieces

For a prototype, there is room to spend more time establishing how each feature should be machined.

An order of approximately 8,000 pieces needs a different approach.

Once the first parts are confirmed, the machining sequence has to remain stable enough for repeat production. Tool wear, cutting conditions and dimensional trends are monitored as the batch continues, particularly around the features identified as critical on the drawing.

The goal is not to inspect quality into the parts after machining. It is to keep the process from drifting in the first place.

That distinction becomes increasingly important as the production quantity grows.

Why Brass Fits This Production Job

Brass machines cleanly and is well suited to small turned components with multiple diameters and secondary machining.

For this project, that helps keep the cutting process efficient across a relatively large batch.

But we do not quote a part simply because it is “18 × 5 mm brass.”

The actual machining cost depends on the number of diameter changes, tool access, secondary milling, tolerance requirements and how efficiently the component can be produced repeatedly.

Our custom brass CNC machining quotations are therefore based on the customer's engineering drawing rather than overall dimensions alone.

Turning and Milling as One Job

A practical machining route for this component includes:

Material Preparation → CNC Turning → Secondary Milling → Deburring → Dimensional Inspection → Packing

The turning operation creates the shaft profile and the main dimensional references. Milling completes the features that cannot be generated around the turning axis.

After machining, burrs around small shoulders and milled areas need to be removed carefully. On a component only 5 mm across, excessive edge finishing can affect a feature much more easily than it would on a large part.

The finished parts need to be clean, but the geometry established during machining still has to remain intact.

Made to the Customer's Drawing

This is not a catalogue pin or a standard brass shaft.

It is a custom machined component produced to the customer's engineering requirements.

That distinction is central to the way we provide custom CNC turning services.

Customers send us their 2D drawings and 3D models, and we review the material, geometry, tolerances, quantity and any features that require operations beyond conventional turning.

Some parts remain entirely on the lathe. Others require drilling, grooving, threading or milling. For components like this one, combining turning with secondary milling is the more appropriate route.

The process is selected for the part rather than forcing every drawing into the same machining method.

Custom CNC Turning Services for Small Precision Components

YS Precision manufactures custom CNC turned parts for medical equipment and other industrial applications, from prototypes to repeat batch production.

Typical work includes small shafts, pins, sleeves, bushings, spacers, threaded components and other drawing-based precision hardware.

We machine brass, stainless steel, aluminum and other specified materials. When a turned component also contains flats, slots, cross holes or other non-rotational features, we can combine CNC turning with milling or turn-mill machining to complete the part.

For small precision components, our quotation is based on what is actually shown on the drawing: material, features, critical tolerances and required quantity.

Small Dimensions, Production-Level Requirements

This brass medical equipment part measures only 18 × 5 mm. What defines the project is not its size, but what has to fit inside those dimensions.

Several turned diameters and shoulders sit close together. Additional features require milling. Selected dimensions are controlled to approximately ±0.01 mm, and the complete machining process needs to remain repeatable across around 8,000 pieces.

That is a typical reason customers look for a custom CNC turning and milling supplier rather than a source for standard turned hardware.

If you have a similar small shaft, pin or custom brass component, send us the drawing together with the material, quantity and critical tolerances. We can review the actual features before recommending the machining route and preparing a quotation.