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Title Block

The title block is the rectangular information area in the lower-right corner of an engineering drawing that contains identifying metadata: company name, drawing number, part name, revision, scale, units, sheet number, drafter, approver, date, default tolerances, and treatment specifications.

The title block is the part of a drawing that gets read first (and often, only). Everything needed to identify, control, and contextualize the drawing lives there. ASME Y14.1 (US) and ISO 7200 (international) define standard title block layouts and required fields.

Standard title block fields:

  • Drawing number - unique identifier, often follows a coded scheme (program-assembly-part)
  • Part name / title - descriptive name
  • Revision letter or number - current revision; A, B, C... or 01, 02, 03...
  • Scale - drawing scale (1:1, 2:1, NTS for not-to-scale)
  • Units - millimeters, inches, decimal vs fractional
  • Sheet number - e.g. SHEET 2 OF 5
  • Drafter / checker / approver - names and dates
  • Default (general) tolerances - applies to all dimensions without explicit tolerance
  • Material, finish, heat treat callouts - sometimes here, sometimes in a separate notes block
  • Third-angle / first-angle projection symbol - tells which projection convention the drawing uses

FAI implications: AS9102 Form 1 (Part Number Accountability) is populated directly from the title block - drawing number, revision, part number, drafter, and applicable specifications all flow from there. An incorrect or missing title block field often causes FAI rejection.

Common pitfalls: revision in title block does not match revision on the change-history block, scale not updated when the drawing is reprinted at a different size, default-tolerance callouts that conflict with general notes elsewhere on the drawing, or mixing units (inches in title block but dimensions in mm).

Related Guides

Best FAI Software, Compared Honestly General Notes First-Angle Projection AS9102 Form 3 ISO 2768mk

Frequently Asked Questions

Where is the title block located?
By convention (ASME Y14.1 / ISO 7200), the title block is in the lower-right corner of the drawing sheet. Some companies also include a smaller corner block in the upper corner with the drawing number for easy identification when filed in cabinets.
What goes in 'default tolerances' in the title block?
The general tolerances that apply to any dimension without an explicit tolerance. Format examples: '±.005 unless otherwise specified' (inches), or 'ISO 2768-mK' (European), or a tabular block by decimal places (e.g. .X = ±.1, .XX = ±.05, .XXX = ±.005).
Why does the projection symbol matter?
It tells the reader which projection convention the drawing uses - third-angle (US standard, view from the right is on the right) or first-angle (ISO standard, view from the right is on the left). Misreading projection direction can cause critical features to be machined on the wrong side.

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