Interpret tolerances without inventing precision
See this course’s project requirements
Collect the six lesson outputs into a set of drawings and calculations for the paper display model.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- Record fractional dimensions and conversions with units and visible arithmetic.
- Produce a labeled scaled front view and a dimension-chain check.
- Calculate an area and quantity estimate using the supplied model data.
- Check whether each sample dimension falls within the stated tolerance limits, including values exactly at either limit.
- Deliver a consistent revised packet with a discrepancy log and independent checks.
Review and revise
Use these criteria to check your work and choose what to improve.
- Numerical accuracy: conversions and estimates recompute correctly.
- Drawing clarity: views, units, scale, and dimension labels agree.
- Judgment: tolerance and missing-information decisions follow stated rules.
- Traceability: revision changes and their affected outputs are recorded.
Want more background?
The idea in everyday life
A target dimension is not always an exact acceptance boundary. Specifications may allow a small interval around it, and measuring equipment may not resolve that interval reliably. This paper exercise provides readings and inclusive limits. It teaches the reasoning needed to ask a useful inspection question without implying that you can certify a manufactured part.
Acceptance compares evidence with an allowed interval.
One step at a time.
Use the sample or information you have permission to use. Keep your work as you go. You can pause between steps.
- 1
Write the target dimension 120 mm and the exercise tolerance ±0.5 mm. Calculate the lower and upper limits and mark that equality at either endpoint is accepted.
- 2
Classify the supplied readings 119.7, 120.5, and 120.6 mm. For each, show the comparison with both limits rather than judging closeness to the target.
- 3
Repeat using a second fictional specification of 80 mm with limits 79.8 through 80.4 mm. Explain why asymmetric limits should be used as written.
- 4
Evaluate a rough whole-millimeter reading near a boundary. Record what the available precision can support and what measurement information remains missing before inspection approval.
- 5
Add an acceptance table to the packet with the specification, reading, decision, and reason. Keep approximate observations visibly separate from the exact supplied practice readings.
See how it works.
Fictional scenario: A decorative insert is specified as 120 mm ± 0.5 mm, with inclusive limits. The allowed interval is 119.5 through 120.5 mm. Readings of 119.7 and 120.5 lie inside it; 120.6 lies outside it. Lee also receives a reading of approximately 120 mm from a ruler marked only in whole millimeters. Lee keeps that as an approximate observation and asks for a suitable measurement before making a borderline acceptance decision. The decimal digits printed in a report are not evidence that the instrument measured them accurately.
Did you cover these?
- The first interval is 119.5–120.5 mm inclusive.
- 120.6 mm is classified outside the interval.
- The rough ruler reading is marked insufficient for a borderline decision.
What to finish
A tolerance table and a note identifying one measurement that needs better evidence.
Watch for this
Calling a part acceptable merely because its rounded reading matches the nominal target.
How can I tell I understand it?
You calculate inclusive limits and distinguish an exercise classification from a real inspection decision.
Quick knowledge check
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Source & access notes · checked 2026-09-10
Opened the Dimensioning chapter; supports dimension placement and tolerances. All numeric limits here are invented for the paper model.
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