Approval Drawings
How to Organize Structural Steel Drawing Numbers and Revisions
How to number structural steel drawings and revisions so indexes, files, transmittals and shop questions all point to the same sheet.
A drawing number is a pointer. If the pointer is ambiguous, every later process — CAD files, PDF names, email subject lines, shop questions — becomes a hunt. Numbering is not bureaucracy. It is how a field superintendent asks for the right brace elevation at 6 a.m.
This article proposes a simple, stable pattern for steel approval and shop sets. You can substitute your fabricator’s existing standard; the rules about uniqueness and revision letters still apply. See also revision management.
Whatever you choose, write it once on the notes sheet and on the cover sheet so guests on the project are not inventing numbers.
Uniqueness first
No two live sheets share a number. Do not reuse a number for a different title when a sheet is voided; void it and start a new number, or the archive becomes lying. Include the project number if files from two jobs ever sit in one folder.
A readable pattern
A pattern such as PROJECT-SET-TYPE-SEQ (for example 2418-APP-PLN-004) is enough. Keep the type codes few: PLN, ELV, TYP, NOT, ERE, SHP. Too many codes and people guess. Too few and a hundred sheets are all “MISC.”
| Element | Example | Rule |
|---|---|---|
| Project | 2418 | Stable for the job |
| Set | APP or SHP | Approval vs shop |
| Type | PLN / ELV / TYP | Short list on the notes sheet |
| Sequence | 004 | Integer, not a speech |
| Revision | C | Not embedded in the number if it will change |
File names follow the number
PDF name = drawing number + revision + short title. No “final” and no desktop names. This is the same discipline as CAD file management.
Shop versus approval
If the same geometry exists in both sets, either share a number series with a set code, or keep parallel series and print the related number on each sheet. Do not let a shop sheet silently replace an approval sheet with the same number and a different title.
Voiding and splitting sheets
When a sheet is split into two, void the old number on the index and issue two new numbers (or keep the old as sheet 1 of 2 if your standard allows). Explain it on the transmittal. Silent splits are how people plot the voided sheet.
A practical workflow
- Publish the type-code list on the notes sheet.
- Assign numbers before drawing, not after plotting.
- Name CAD and PDF files to match.
- Show numbers and letters on the index.
- Never recycle a live number.
Engineering tips
- Leave gaps in sequences (10, 20, 30) if you expect inserts; or accept 14A if your standard allows suffixes.
- Avoid characters that break file systems: / \ : * ?.
- Train the shop to quote number and revision, not “the roof drawing.”
Common mistakes
Numbering by the order you happened to draw
Then related elevations are scattered. Number by type, then by grid or level.
Two offices, two systems, one job
Pick one at kickoff. Translating numbers mid-job is a tax.
Changing a number after comments were issued
You orphan the reviewer’s mark-ups. If you must change it, map old to new on the transmittal.
Checklist
- Numbers unique
- Type codes listed
- Revision not inside the number
- File names match
- Index matches files
- Voided numbers stay void
- Set code distinguishes approval vs shop
Frequently asked questions
Should piece marks equal drawing numbers?
No. Piece marks identify steel. Drawing numbers identify sheets. They cross-reference; they do not collide.
Can we use only sequential numbers?
Yes for tiny jobs. As soon as you have plans, elevations and typicals, type codes pay for themselves.
What about model views instead of sheets?
If the contract allows model review, you still need a named, dated view or package identifier. An unnamed 3D file is not a number.
How does this interact with automation?
Generators need the number as a field. Do not let the generator invent numbers that the index does not know.
Where this leaves the work
If a superintendent can request a sheet by number and get one file, your system works. If they have to describe the drawing, it does not.
Tie numbering to revision control so the letter and the number never tell different stories.
This article provides general educational information. Project-specific structural design, calculations and drawings should be reviewed by appropriately qualified engineering professionals and checked against applicable project requirements and standards. StruTools does not replace engineering judgement or professional design review.