The short answer
What this setting controls
Regular tolerance suits most enclosures and prototypes. Precision tolerance is for a mechanical interface that cannot absorb ordinary manufacturing variation.
Set tolerance from the enclosure stack, datum scheme, routing method, plated features and inspection capability. Do not specify a tight tolerance without a measurement and acceptance plan.
Options in the order form
How the available choices differ
| Choice | Use it for | Engineering note |
|---|---|---|
| ±0.2 mm regular | Most routed outlines | Use when the enclosure and mating features provide normal clearance. |
| ±0.1 mm precision | Tight mechanical interfaces | Dimension the critical datum and verify the tolerance stack with the enclosure. |
Compatibility
What can change with this selection
- Precision can add cost or remove compatible routing choices.
- The tolerance controls the outline, not every copper-to-edge clearance rule.
- If the page disables a choice, treat it as a compatibility result and adjust the controlling design decision rather than forcing the value.
Practical recommendation
How to make the decision
- Use Regular for ordinary boards.
- Use Precision only where the mechanical or optical interface needs it.
- Put critical datums and inspection dimensions in the fabrication drawing.
Before release
Check these points before adding the quote to cart
- Confirm the selected value matches the released Gerber, drawing, stack-up, BOM or assembly plan.
- Review any fields that changed automatically after this selection.
- Check the board preview and server-calculated estimate before adding the quote to cart.
- Use Regular for ordinary boards.
- Use Precision only where the mechanical or optical interface needs it.
- Put critical datums and inspection dimensions in the fabrication drawing.
Frequently asked questions
Answers for ordering and design review
Is tighter always safer?
No. A tighter number without the right process and inspection can create an unrealistic requirement.
When should I change Board outline tolerance?
Change it when the released electrical, mechanical, thermal, assembly or quality plan gives a measurable reason. Otherwise keep the compatible default and review the resulting board preview and estimate.
Why is an option disabled?
The current material, geometry, layer count, quantity or another selected process makes that combination unavailable. Change the controlling selection or revise the design package rather than trying to bypass the disabled state.
Can I rely on the online choice as final manufacturing approval?
No. The interface screens known combinations and requests pricing, while final manufacturability remains subject to the released files and technical review.
What should I record outside the order form?
Put controlled requirements in the fabrication drawing, assembly drawing, stack-up, BOM or acceptance plan. Use Special instructions only for a concise pointer to that controlled requirement.
Will changing this update other selections?
It can. The order form re-evaluates compatibility and may replace a now-invalid dependent choice before requesting a fresh server-side estimate. Review every highlighted or automatically changed field.
What if the design requires an option that is not offered?
Do not approximate it with a different label. Recheck the controlling material and geometry, document the actual requirement, and request technical review before placing the order.
Useful engineering tools
Calculators and preparation guides
Further reading
Standards and technical references
Use the latest applicable revision and your organisation’s controlled requirements when a standard forms part of product acceptance.