Inspection Sheet Template for Sheet Metal Parts: A Complete Guide for Quality Engineers

Quick answer: An inspection sheet template for sheet metal parts is a structured document that links every dimension, tolerance, and GD&T callout on a drawing — via sequential balloon numbers — to measured values recorded by the inspector. It covers linear dimensions, bend angles, bend radii, hole patterns, surface finish, and material verification, and forms the basis of a sheet metal FAI inspection report under AS9102 Rev C or PPAP.

Sheet metal inspection sheets fail audits more often than those for machined parts, and the reason is structural rather than inspector error. Bend callouts alone can generate three separate characteristics per bend line — angle, inside radius, and flange length — each needing its own balloon number and its own row. A drawing with eight bends can carry 24 bend-related characteristics before a single linear dimension or GD&T callout is counted. Without a template built specifically for sheet metal geometry, rows get merged, balloon numbers drift out of sequence, and the first article package arrives at the customer with gaps an auditor will find in minutes.

The fix is a properly structured inspection sheet, built directly from the ballooned drawing before a single measurement is taken. This guide walks through exactly how to build one.

Why Sheet Metal Inspection Sheets Are Harder Than They Look

Sheet metal parts carry a category of dimensions that do not appear on machined components: bend angles, inside bend radii, developed (flat) lengths, and springback-affected angles. Each bend line on a drawing may carry two or three separate callouts, and all of them need individual balloon numbers and individual rows on the inspection sheet.

Combine that with tight flatness requirements after forming, punched hole true-position tolerances relative to a datum edge, and surface finish specifications for coated parts, and you have a document that is genuinely complex to organise. Miss a characteristic, and your sheet metal FAI inspection report is immediately non-conforming at the customer review.

The stakes are straightforward: a missing or mislabelled dimension on the inspection sheet means either a re-inspection (cost and delay) or a non-conforming part shipped to the customer (far worse). Getting the template right the first time is the only sensible path.

Anatomy of a Sheet Metal Inspection Sheet Template

A robust template has four distinct zones: the header block, the drawing reference block (ballooned drawing), the characteristic table, and the sign-off block. Each zone has mandatory fields.

Zone 1 — Header Block

• Part number and revision level
• Part name and description
• Material grade (e.g., CR4 cold-rolled steel per IS 513, or 5052-H32 aluminium per ASTM B209, or 304 stainless per ASTM A240)
• Material thickness (nominal ± tolerance)
• Finish / coating specification (e.g., powder coat RAL 9005, 60–80 µm DFT)
• Drawing issue date and drawing number
• Customer / end-use program
• Inspection date and lot/batch number
• Applicable standard (ISO 2768-m general tolerance, ASME Y14.5-2018 for GD&T)

Zone 2 — Ballooned Drawing Reference

Attach or embed the ballooned drawing as a PDF or image. Every balloon number on the drawing must have a matching row in the characteristic table below — no exceptions. This cross-reference is the document's audit backbone, and it is exactly what AS9102 Rev C Form 3 requires for aerospace FAI submissions.

Related reading: What Is Ballooning a Drawing? Meaning and Guide and AS9102 Forms 1, 2 & 3 Explained: FAI Guide.

Zone 3 — Characteristic Table (the core of the template)

This is where quality engineers spend most of their time. The table below shows the recommended columns for a sheet metal inspection sheet. Note that bend characteristics require their own dedicated rows.

Zone 4 — Sign-Off Block

• Inspector name, signature, and date
• QA reviewer name and signature
• Overall disposition: Accept / Reject / Accept on Deviation
• NCR reference number (if applicable)

How to Build the Template Step by Step

1. Retrieve the latest drawing revision. Confirm the revision letter matches the purchase order. A single revision mismatch invalidates the entire inspection sheet.
2. Identify all characteristic types before ballooning. Go through the drawing and categorise every callout: linear dimensions, bend angles, inside radii, hole diameters, true positions, flatness, surface finish, material callout. Count them — this is your expected row count.
3. Balloon the drawing sequentially from left-to-right, top-to-bottom. Use a consistent scheme: start at the title block view and work through each view in reading order. In the CadNexa PDF Balloon Tool, Box+Balloon OCR mode lets you draw a rectangle around a dimension — the tool reads the value, tolerance, and type (angle, diameter, radius, GD&T) via OCR and pre-fills the balloon data automatically, eliminating manual transcription errors at source.
4. Handle bend dimensions with care. For each bend line, create separate balloon numbers for: (a) the bend angle, (b) the inside bend radius, and (c) the developed length or flange dimension, if all three are called out. Do not combine them in one balloon. A typical sheet metal part with six bends can generate 12–18 separate bend-related rows on the inspection sheet.
5. Add GD&T rows in order. Balloon each feature control frame as a separate characteristic. Record the GD&T symbol, datum references, and tolerance value. For example: Flatness ⏥ 0.3 mm — no datum. True position ⊕ Ø0.2 mm [A][B][C]. Reference Feature Control Frame Explained: How to Read GD&T for interpretation guidance.
6. Assign general tolerances to un-toleranced dimensions. Dimensions without explicit tolerances fall under the drawing's general tolerance block, typically ISO 2768-m for sheet metal. Always note which standard applies in the remarks column so auditors can verify the tolerance source.
7. Select and document measurement methods. For bend angles: digital protractor or CMM angle measurement. For hole true position: CMM with the relevant datum scheme set up. For flatness: surface plate and dial gauge, or CMM scanning. Record gauge calibration ID and due date in the sign-off block.
8. Generate the FAI report if required. If the part is a first article, the characteristic table from your inspection sheet becomes AS9102 Rev C Form 3. Every balloon number must appear on both the ballooned drawing and Form 3 — they are cross-audited. The CadNexa FAI Report Generator produces Form 3 directly from balloon data in AS9102 Rev C, PPAP, ISO, ASME, DIN, JIS, GB, and IS formats, exportable as interactive HTML, PDF, or CSV.
9. Verify completeness before sign-off. Row count in the characteristic table must equal the total balloon count on the drawing. Any gap is an audit finding waiting to happen.

Ballooning Bend Dimensions on Sheet Metal Drawings — In Detail

Bend callouts are the most frequent source of errors on sheet metal inspection sheets. Here is a structured approach to interpreting and ballooning them correctly.

A typical bend note reads: R3.0 / 90° ± 0.5° / Flange = 25.0 ± 0.3. That is three separate characteristics, each needing its own balloon and row. Assign them consecutive numbers — say, Balloon 12 (bend radius), Balloon 13 (bend angle), Balloon 14 (flange length). This keeps the inspection sheet unambiguous and makes CMM programming straightforward.

For springback-affected angles, note on the inspection sheet whether the measurement was taken at the free state or under fixturing. ASME Y14.5-2018 Section 4.20 covers free-state variation for non-rigid parts — sheet metal qualifies. If the drawing specifies a restrained condition, document the restraint method used during measurement.

Developed (flat) lengths are sometimes shown only on the flat pattern view. If your drawing has both formed and flat pattern views, balloon the flat pattern dimensions separately and label them clearly as "flat pattern" in the description column. This prevents confusion during CMM setup.

For authoritative tolerance values across bend intervals, the ASME Y14.5-2018 standard is the reference for GD&T callouts, and ISO 2768 covers general tolerances for sheet metal dimensions not explicitly toleranced on the drawing.

Sheet Metal FAI Inspection Report Format

When a first article is required — aerospace under AS9102 Rev C, automotive under AIAG PPAP, or general manufacturing under a customer-specific format — the inspection sheet becomes a formal submission document. The structure maps directly to the template described above, but with stricter traceability requirements.

For AS9102 Rev C Form 3, each row must carry: characteristic number (balloon), characteristic class (key / critical / major / minor — defined on the drawing), nominal, tolerance, actual measured value, and conformance. Missing the characteristic class field is one of the most common audit findings on aerospace sheet metal FAI packages.

Related: Free FAI Report Template: AS9102 Forms 1–3 and PPAP Dimensional Results Report Format & Example.

Common Mistakes on Sheet Metal Inspection Sheets

• Ballooning the same feature twice with different numbers. Happens when two engineers balloon the same drawing independently. Always lock the ballooned PDF as the master and do not re-balloon.
• Using the wrong general tolerance class. Applying ISO 2768-c (coarse) when the drawing specifies ISO 2768-m causes inflated pass rates. Always check the drawing title block explicitly.
• Forgetting to balloon surface finish callouts. Ra values, coating thickness, and plating adhesion are inspectable characteristics. They need balloon numbers and rows like any other dimension. Per ASQ guidance on surface finish, surface texture should be part of any complete inspection plan.
• Recording bend angle without specifying datum or measurement method. "Measured with protractor" is not sufficient. Record the gauge ID, calibration due date, and whether the part was fixtured or free-state during measurement.
• Skipping hole-pattern true position on simple bracket drawings. Quality engineers sometimes assume punched holes are visually acceptable. True position Ø0.5 mm [A][B] is a real GD&T callout requiring a real measurement, not a visual check.
• Misaligning balloon numbers between the drawing and the report. If balloon 15 on the drawing is the bend angle but the inspection sheet row 15 is a hole diameter, the audit cross-reference fails immediately. Number gaps after deleting a balloon are a common culprit — use a tool that auto-fills gaps on delete.

How CadNexa Helps

Building a sheet metal inspection sheet from a PDF drawing is the exact workflow CadNexa's live PDF Balloon Tool is built for. In the browser — no installation — you open the drawing, use Box+Balloon OCR mode to draw a rectangle around a dimension, and the tool reads the value, tolerance, and type (angle, diameter, radius, GD&T) and pre-fills the balloon data. Smart Detect scans the whole drawing in one click and auto-detects dimensions and GD&T frames for review. Continuous numbering handles gaps automatically when you delete a balloon, so your sheet metal FAI inspection report never has a sequence error.

Once ballooning is complete, the FAI Report Generator (live feature) creates the AS9102 Rev C Form 3, PPAP dimensional results table, or ISO/DIN/JIS equivalent directly from your balloon data — exported as interactive HTML, PDF, or CSV. The CSV Export lets you pull all balloon characteristics into Excel or your in-house QMS without retyping a single value.

Guest sample mode is available at cadnexa.com — try the Balloon Tool with bundled sample drawings without signing up.

Frequently Asked Questions

What should an inspection sheet template for sheet metal parts include?

It must include a ballooned drawing reference, part number and revision, material grade and finish, all linear and bend dimensions with tolerances, GD&T callouts (flatness, true position, angularity), surface finish, hole diameters, and pass/fail fields linked to each balloon number. Missing any characteristic category leaves the sheet incomplete for FAI or incoming inspection purposes.

How do I balloon bend dimensions on a sheet metal drawing?

Assign a sequential balloon number to each bend callout separately — bend angle, bend radius, and flange/developed length each get their own number and their own row in the inspection sheet. Record nominal value, tolerance, and measured value in the corresponding row. Never combine two characteristics under one balloon number.

Which tolerance standard applies to general sheet metal dimensions?

ISO 2768-m (medium class) is the most widely used general tolerance for sheet metal fabrication. Tighter applications reference ISO 2768-f (fine). For aerospace sheet metal, AS9102 Rev C drives the FAI format and ASME Y14.5-2018 governs GD&T callouts. Always read the title block to confirm which standard the drawing invokes before completing the inspection sheet.

What is the correct format for a sheet metal FAI inspection report?

A sheet metal FAI inspection report under AS9102 Rev C uses Form 3 (Characteristic Accountability). Each row carries a balloon number, characteristic description, nominal value, tolerance, measured value, and conformance status. The ballooned drawing is submitted alongside Form 3 so the customer or auditor can cross-reference every callout directly. Under AIAG PPAP, the equivalent is the Dimensional Results section with an attached ballooned drawing.

Can I export my sheet metal inspection sheet as a CSV for my CMM or Excel?

Yes. Once you have ballooned the drawing and reviewed characteristics in CadNexa, the live CSV Export feature downloads all balloon data — balloon number, nominal, tolerance, type, and description — for import into Excel, an in-house QMS, or CMM inspection planning software. This eliminates manual re-entry and reduces transcription errors between the drawing and the measurement system.

Conclusion

A well-structured inspection sheet template for sheet metal parts is not a bureaucratic formality — it is the document that connects every dimension on the drawing to a measured, traceable result. Getting the template right means ballooning every characteristic (including each bend callout separately), applying the correct tolerance standard, documenting measurement methods, and matching the format expected by your FAI or PPAP submission standard.

The fastest way to move from drawing to complete inspection sheet — without transcription errors or missed balloons — is to balloon the PDF directly and generate the report from that data.