Custom Dimension 4130 Tubing
Custom dimension tubing is about control as much as size. When a tube has to fit a bearing, slide inside another tube or clean up to a finished diameter, the tolerances matter more than the nominal numbers.
When Custom Dimensions are Needed
Custom dimensions are appropriate when:
- The application requires a very specific bore dimension that cannot be achieved by standard OD/wall combinations
- The design requires an OD or wall outside the standard catalogue range
- The application requires tighter tolerances than standard ASTM A519 CDS permits
- A large volume is required at a non-standard dimension that justifies a mill production run
Custom Dimension Enquiry Requirements
For custom dimension enquiries, provide:
- Required OD (actual, in decimal inches or mm)
- Required wall (actual, in decimal inches or mm) or required bore if the bore is the controlled dimension
- OD and wall tolerance class required
- Required length and total footage or weight
- Applicable standard
- Condition requirement
- Application description
- Timeline
| Parameter | Custom Dimension Enquiry |
|---|---|
| OD | Exact required OD — not a nominal size |
| Wall | Exact required wall — or specify required bore |
| Tolerances | Tighter than ASTM A519 standard if required |
| Quantity | Total footage or weight — minimum quantity applies |
| Standard | Applicable specification for the custom product |
| Lead time | Custom dimensions require mill order — longer lead time |
| MTC | Required — state at enquiry |
How to Dimension a Custom Tube
A tube has three related dimensions: outside diameter, inside diameter and wall. Only two can be held closely at once, because the third follows from them. Decide which two matter for your part. For a telescoping fit, control the OD of the inner tube and the ID of the outer tube. For a part machined on the outside, control the ID and wall.
State the tolerance on each controlled dimension, and mention straightness or ovality if they affect the fit. Give the quantity, condition and end use. Requirements that simply need a standard tube to a tighter limit may be met by selection from existing material, which is quicker than a special run. See 4130 precision tubing for tolerance background and custom sizes for non-standard diameters.
Frequently Asked Questions
Is there a minimum order quantity for custom dimension 4130 tubing?
Custom mill orders typically have minimum tonnage requirements that vary by the mill and dimension. For small quantities of non-standard dimensions, the economics may not be viable. Confirm minimum quantity at the RFQ stage.
Can I specify both OD and ID tolerances?
Yes. When OD and ID are controlled, the wall follows from them and is not separately toleranced.
What if I only need a tighter tolerance on a standard size?
Say so. It may be possible to meet it from standard production without a special order.
Custom Dimension 4130 Enquiry
Provide exact OD, wall (or bore), tolerance class, quantity, standard, and application for a custom dimension feasibility assessment.
- Required OD (exact)
- Required wall or bore (exact)
- Tolerance class
- Total footage or weight
- Applicable standard
- Condition
- Application description
- Timeline