Diameters, shoulder lengths and fits
Include the requirement or identify it as an open question for the project review.
CAPABILITIES
We make custom CNC turned parts for assemblies that depend on accurate diameters, shoulders and threads. Send a shaft, sleeve, spacer or adapter drawing for a review of the turning and any additional milling operations.
The workpiece rotates while a tool forms its profile. A part with off-axis holes or flats may require additional milling operations.
Typical part types: Shafts, sleeves, spacers and threaded adapters.

On a shaft, a bearing seat, seal contact and free-clearance section do different jobs. Treating all three as the same tolerance can increase inspection and machining work without improving the assembly. Identify the mating component and label the functional surfaces on the drawing.
| Custom turned part | What to identify | Why it changes the manufacturing plan |
|---|---|---|
| Stepped shaft | Bearing seats, shoulders, reference axis and runout | The setup must connect the relevant diameters and faces |
| Sleeve or bushing | Bore fit, outside fit, wall thickness and installed condition | Clamping and inspection must suit a thin or flexible section |
| Threaded adapter | Thread standard, pitch, class and engagement length | Similar-looking thread profiles can have incompatible fits |
| Spacer | Length tolerance, parallel faces and bolt clearance | Length may control the assembly while the outside diameter is less critical |
These features add a relationship to the rotational geometry. Show which flat locates a cross-hole, or how a keyway lines up with a shoulder. If a second operation is needed, those relationships must remain controlled when the part moves between setups. A section view is especially useful when a cross-hole must meet an internal passage.
A modeled cylinder does not specify a thread. Put the full thread designation on the drawing and say whether depth refers to full usable thread or the drilled hole. For a sealing adapter, separately identify the sealing face; a correct thread alone does not define a leak-tight connection.
Suppose the sleeve bore locates on a shaft and its outside diameter fits a housing. Sending only the nominal diameters leaves two fit decisions open. Provide the shaft and housing limits or the intended fit designations, identify the inspection condition, and show whether the sleeve is measured loose or after installation. This is a drawing-review example, not a production result.
Our recommendation is to resolve both fits before approving the sleeve sample. Testing only the shaft fit can leave the housing interference undiscovered until assembly. Use the assembly and part drawing checklist to keep those interfaces together.
Brass turned components suit many fitting and spacer designs. Aluminum, stainless steel and alloy steel are other material families we review against the application. State the grade, condition, exposed environment and any finish restrictions; describe which dimensions are accepted after finishing.
For a sample, name the fit or assembly test it must answer. Production orders start at 100 pieces per part number, counted separately for each part. Prototypes and sample parts are quoted from a single piece. Design-only projects are quoted separately. Include the quantity separately for each part number and attach the current PDF and STEP files.
PREPARE YOUR PROJECT
Include the requirement or identify it as an open question for the project review.
Include the requirement or identify it as an open question for the project review.
Include the requirement or identify it as an open question for the project review.
Identify the application before choosing a grade. Discuss material condition, critical surfaces and whether dimensions apply before or after finishing.
Browse the material libraryYOUR QUESTIONS, ANSWERED
Find practical answers before starting a project.
Include the thread designation, pitch, depth and any fit requirement on the drawing. A cylindrical hole in a model does not define these details.
Choose “Help me choose” in the inquiry. Explain the application and environment so the options can be reviewed against the function of the part.
We provide a quotation within 24 hours. Estimated delivery is 3–7 days after the order, drawings and required upfront payment are all confirmed: full payment for new customers or the agreed deposit for returning customers. Returning customers pay the balance before shipment.
In-house service
These tables provide process-planning references, not measured limits for a specific machine or factory. Dimensions are in millimeters unless stated otherwise. We confirm the usable size, tolerance, material and inspection requirements together in your quotation.
| Parameter | Reference / planning value | Application |
|---|---|---|
| Typical maximum part | Ø500 × 1500 mm | Material and machine setup determine the usable envelope. |
| Minimum diameter | Ø1 mm | Depends on geometry, material and support. |
| Standard dimensional tolerance | ±0.01 mm | — |
| Tight dimensional tolerance | ±0.005 mm | Selected features after drawing review. |
| Recommended internal radius | ≥0.5 mm | — |
| Thread size / engagement | M1.6+; ≥1.5 × diameter | Confirm strength and assembly requirements. |
| Recommended metal wall | ≥0.8 mm | — |
| Hole diameter / depth | Ø ≥0.5 mm; depth ≤10 × diameter | Deep-hole setup depends on material and length. |
| Engraved text | Height ≥2 mm; depth ≥0.5 mm | — |
LET’S MAKE IT TANGIBLE
Bring a drawing. Bring a sketch. Start the conversation.