Dimensional inspection and tolerances
How to check a formed piece against its order: the tool for each check, thickness bands by material, the AFS limits and a fixed inspection sequence. It also covers stack-up, common defects and recording the evidence a reviewer needs.
4 lessons · about 45 min · 10 diagrams · 3 videos
Version 1.1.0
Builds on these modules
Lessons
0 of 4 complete
Lesson 1 · 11 min · 11 slides · 10 questions
Dimensional inspection and tolerances: principles and terminology
What a formed piece is checked against, the words inspection uses, the tool for each check, and why zero, calibration and traceability are different things.
You will be able to: Define nominal, tolerance, mold line and Blank Width, name the tool for each check and what zeroing and calibration mean, and state the safety boundaries of measuring at the folder.
Not startedStart →Lesson 2 · 12 min · 11 slides · 11 questions
Dimensional inspection and tolerances: materials, standards and design constraints
Thickness bands by material, which standard governs each, the AFS limits every piece must meet, what project specifications ask for, and flatness.
You will be able to: Find the thickness band for galvanized and copper, say which standards hold the aluminum and stainless bands, apply the AFS limits, and read a project specification for its acceptance language.
Not startedStart →Lesson 3 · 13 min · 12 slides · 10 questions
Dimensional inspection and tolerances: methods and worked application
The inspection sequence, what to do when a reading is out of band, tool technique, and five worked checks with their arithmetic.
You will be able to: Inspect a formed piece in a fixed order, use the micrometer, caliper and tape correctly, and work thickness, Blank Width, stack-up and piece-count checks with every input stated.
Not startedStart →Lesson 4 · 9 min · 10 slides · 7 questions
Dimensional inspection and tolerances: defects, verification and case study
Defects an inspector catches, why oil canning is judged by the contract, how to record a check, and a worked case study with its findings.
You will be able to: Recognize the common dimensional defects, decide between re-measuring, holding and remaking against the order, and record the evidence a reviewer needs.
Not startedStart →
Practical task
Inspect one formed flashing piece (a real order, or the case-study profile) against its order and produce an inspection record a reviewer can check against its sources.
Hand in
- An order summary: material, gauge or thickness, finish and painted face, each leg, angle and direction, hems, Blank Width, length and count, and where the governing tolerance comes from (order, spec or standard)
- A tool list with the zero check result for each tool and the time it was done
- A measurement sheet: thickness in three places, each leg to the mold line, each angle and direction, hem end, face, return and gap, painted face, length and piece count, with units
- A decision for each check (pass, re-measured, hold), with any re-measurement recorded
- A defect analysis of one fault found or set up: what it was, which rule or order value it breaks, and the correction
Rubric
| Criterion | Meets the standard when |
|---|---|
| Governing tolerance | The record names where each acceptance band comes from and states none from memory. |
| Thickness | Three readings are recorded after a zero check and compared with the correct band for that material and coating. |
| Geometry | Every leg is to the mold line, every angle has its direction, and the hem end, face, return and gap are checked against the order and the AFS minimums. |
| Length | Length and count are checked, the piece length used (120 in standard or 126 in maximum) is stated, and tape error is considered. |
| Out-of-band handling | Out-of-band readings are re-zeroed and re-measured, then held and flagged, never rounded into the band. |
| Safety | The record notes that pieces were measured off the machine and the hand protection used for cut edges. |