This is a batch of aluminum lens tubes we machined for an optical instrument application. Each part is a cylindrical housing with a mirror-polished interior, a precision-chamfered top edge, and a custom-shaped slot milled into the side wall. We produced 200 pieces in this batch.

After turning, we moved to CNC milling for the side slot. The slot geometry includes straight edges and internal radii that required careful toolpath planning to machine cleanly without leaving marks on the surrounding surface. Once milling was complete, we removed all burrs from the milled edges before doing a final cleanup of the part.

Parts were inspected by sampling across the batch, covering the following key dimensions:

• Inner bore diameter and roundness
• Overall height and wall thickness
• Slot position, width, and depth
• Top edge chamfer angle and consistency
• Interior surface finish from fine turning

For a batch of 200 pieces, keeping dimensions consistent across all parts is as important as getting the dimensions right on the first piece. Variations in bore diameter or slot position between parts can cause assembly issues when multiple units are used interchangeably in the same optical system.

We used the same CNC program and tooling setup throughout the entire batch without making adjustments between parts. Tool wear was monitored during production, and tools were replaced at set intervals to prevent any gradual drift in dimensions. Sampling inspections were carried out at regular intervals during the run to catch any variation early.

We completed the batch of 200 pieces and delivered them within the agreed lead time. Parts were inspected by sampling before shipping. The customer confirmed the parts fit their optical assembly without any adjustments needed.

Part type: Custom Aluminum Lens Tube

Material: Aluminum 6061-T6

Machining Process: CNC Turning + CNC Milling

Surface Finish: As-Machined

This type of CNC machined aluminum lens tube works well across a range of optical instrument applications. In microscopy, lens barrels like this are used to house objective lenses and keep everything in precise optical alignment — any variation in the bore diameter or concentricity directly affects image quality. In laser equipment, the mirror-finish interior makes a real difference, as surface quality inside the beam path affects how the light travels through the system. In industrial inspection and machine vision setups, consistent dimensions across a batch matter more than anything else, since multiple units often need to fit into the same assembly interchangeably.

The combination of turning for cylindrical accuracy and milling for the custom slot makes this a practical approach for optical component production at this kind of volume. Have a similar optical component that needs CNC turning and milling?

We provide custom CNC machining services for low-volume production and Rapid Prototyping for design verification.  Click Here to Upload Your CAD Files