Quick answer: Choose datums that relate inspection to functional mounting and motion. Convenient free-state dimensions may not describe the installed part.
Which datum should control a strip spring drawing?
State which dimensions apply in free, restrained or assembled condition. A coiled strip can move while being measured, so datum and fixture definitions are essential. Coordinate the spring drawing with the mating assembly instead of leaving each supplier to invent a reference.
A practical verification method
Compare drawing measurements with the installed functional positions using the approved restraint and fixture.
| Item | What to record | Purpose |
|---|---|---|
| Reference configuration | Part or assembly identity and drawing revision | Make comparisons traceable |
| Test conditions | Relevant position, direction and operating condition | Compare the same characteristic |
| Decision evidence | Compare drawing measurements with the installed functional positions using the approved restraint and fixture. | Resolve the specific question before approval |
Use the result in an engineering request
Describe the observed condition and the required function separately. Include the relevant drawing revision and your results from the check above. If an acceptance limit has not been established, identify it as an open design input rather than treating a successful trial as approval.
Review the related Leading Spring product information. For a project-specific review, send the mechanism description, available geometry and the evidence relevant to this decision through the contact page.
Editorial note: AI-assisted engineering guidance, prepared from the topic-specific reasoning shown here and the company’s public product context. Illustrations explain decisions; they are not customer-case photographs or test results. Product-specific suitability requires review against your approved requirements.