The replacement standard, ISO 81714 (Design of graphical symbols for use in the technical documentation of products), is now the authoritative document. It consists of two main parts:

The updated standard requires a 0.5 mm minimum gap when lines cross without connection. The 2002 version allowed a simple crossing line. Diagrams not showing gaps will be rejected in ISO 9001 audits.

If you landed here searching for “iso 146173 pdf updated,” you may also encounter these similar misspellings. Here is the correction guide:

| Misspelled search | Correct standard | |-------------------|------------------| | iso 146173 pdf | iso 14644-3:2019 | | iso 146173 1 | iso 14644-1:2015 | | iso 146173 2 | iso 14644-2:2015 | | 146173 standard | iso 14644-3 (test methods) | | iso 146173 free download | Not available legally – try ISO’s preview |

Pro tip: Bookmark the official ISO search page. Always verify the standard number before clicking “buy PDF.”

The updated standard now strictly defines line hierarchy:

Previous versions only offered recommendations.

If you do diagram design, CAD library creation, or technical documentation → buy the 2021 version.

If you just need to read symbols for a specific project → check if your employer already has an ISO subscription or use IEC 60617 as a free alternative.

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If you purchased a PDF from a third-party vendor (e.g., eBay, some online document stores) claiming to be the updated ISO 14617-3 but it’s actually the 2002 edition:

Warning: Many websites claiming "iso 146173 pdf updated free download" are fake. They often provide: