Brass CNC Turned Parts with Secondary Milling for Musical Instrument Hardware

This brass component was custom machined for a musical instrument application and shipped to a customer in the United States. At approximately 30 × 18 mm, it is compact, but its geometry requires more than a straightforward lathe operation.

The outside is largely rotational, with a cylindrical body, bottom flange and a repeated thread-like or grooved profile. Inside, the geometry changes. A recessed cavity is combined with holes and local machined features around the inner wall.

The machining route follows that geometry: CNC turning establishes the main concentric features, while secondary milling and drilling complete the details that cannot be produced by turning alone.

Project Details

The component is produced from the customer's engineering drawings rather than modified from a standard fitting or catalog part.

The Outside Is Naturally a Turning Job

The exterior gives the machining process a clear starting point.

The cylindrical body, flange, end faces and concentric diameters are well suited to CNC lathe machining. The central opening can also be bored while the component remains referenced to its main rotational axis.

Around the outside is a repeated profile resembling a coarse thread or series of grooves. Its exact specification cannot be determined from the photograph alone. Pitch, depth, diameter and profile are machined according to the customer's drawing.

This is common in custom CNC turning. Two parts may look similar at first glance while having very different dimensions, profiles and assembly requirements.

Once the round geometry is established, however, the lathe has done only part of the job.

Inside, the Geometry Stops Being Rotational

Looking into the component explains why secondary machining is required.

The recessed cavity contains holes and local features that do not continue uniformly around the circumference. These details require the cutting tool to approach from directions other than the main turning axis.

They are completed by CNC milling and drilling.

A typical process for this type of component may be:

CNC Turning → Internal Boring → CNC Milling & Drilling → Deburring → Inspection

If the final drawing contains additional off-axis features, turn-mill equipment may also be considered. The decision depends on the geometry and production requirements.

There is little value in putting every operation on the most complex machine available. Turning handles the round geometry efficiently; secondary machining is introduced where the design actually needs it.

The Important Part Is Where the Features Meet

Producing the outside and inside separately is not enough. Their positions need to agree with the drawing.

An internal hole may be located from the center axis. Another feature may be dimensioned from the flange face or an outside diameter established during turning.

Those references have to be maintained when the component is repositioned for milling or drilling.

This makes workholding and datum selection an important part of the process.

For CNC turned parts with secondary machined features, an individual hole or pocket may be relatively simple to cut. Locating it correctly in relation to the turned geometry is often the more meaningful manufacturing requirement.

Brass Works Well Across the Different Operations

Brass is a practical material for this combination of machining processes.

The component requires several types of cutting:

Turning + Boring + External Profile Machining + Milling + Drilling

Good machinability helps when moving from larger rotational features to smaller internal details, particularly on a compact component with limited working space.

The exact brass alloy still follows the customer's specification. We do not assign a grade based on appearance alone.

When requesting a quotation for brass CNC machining, providing the actual alloy helps with material sourcing, tooling decisions and pricing.

Planning the Secondary Operations for 3,000 Parts

The production quantity for this project is approximately 3,000 pieces.

At this volume, the secondary machining cannot be treated as an occasional manual operation added after turning.

The part needs to be located consistently so that the internal holes and milled details maintain their specified relationship to the already-machined outside surfaces.

Fixture design, tool access and operation sequence therefore become part of the production plan.

Depending on the geometry, the best route may be CNC turning followed by a dedicated secondary setup, or a more integrated turning-and-milling process. What matters is choosing a method that can be repeated efficiently across the batch while continuing to meet the drawing.

Precision CNC Turning Services for Custom Parts

YS Precision provides precision CNC turning services for non-standard components manufactured from customer 2D drawings and 3D models.

Our machining capabilities include:

• CNC turning
• CNC lathe machining
• Precision boring and grooving
• Internal and external threading
• CNC milling
• Drilling and tapping
• CNC turn-mill machining
• Secondary CNC machining

We manufacture brass CNC turned parts, threaded components, bushings, sleeves, housings and other custom CNC machined parts. Materials also include aluminum, stainless steel, copper, carbon steel and engineering plastics.

Our work ranges from conventional rotational parts to components like this one, where turning establishes the basic form and additional CNC machining completes the remaining geometry.

When the Drawing Calls for More Than Turning

From the outside, this component is largely a brass CNC turned part. The internal cavity tells the rest of the manufacturing story.

The flange, concentric surfaces and external profile make turning the natural starting point. The internal holes and local features then bring milling, drilling, fixturing and feature positioning into the same project.

For similar made-to-print CNC components, the complete engineering drawing is the best place to start. Share the 2D/3D files, material specification, quantity and critical dimensions, and we can review how the part should move from turning into secondary machining.

YS Precision provides custom CNC turning and secondary machining for parts whose geometry goes beyond a standard lathe operation.