Engineering · Drawing Standards
Drawing template reference.
Title block, standard notes, default tolerances, GD&T frame templates, and revision conventions. Copy-paste-able language for your drawing template — and the standard format we expect on inbound drawings.
Sheet sizes
Standard ANSI and ISO sheet sizes.
| ANSI | Size (in) | ISO | Size (mm) | Typical use |
|---|---|---|---|---|
| A | 8.5 × 11 | A4 | 210 × 297 | Letter — small parts, parts list, simple components |
| B | 11 × 17 | A3 | 297 × 420 | Tabloid — moderate complexity parts |
| C | 17 × 22 | A2 | 420 × 594 | Standard CNC drawing for most parts |
| D | 22 × 34 | A1 | 594 × 841 | Large or complex parts, assemblies |
| E | 34 × 44 | A0 | 841 × 1189 | Large assemblies, weldments, layouts |
Title block
What every drawing needs in the bottom-right.
A standard title block contains everything needed to identify, manufacture, and inspect the part. The minimum required fields, plus what we’d like to see for clean handoff:
Standard notes
Copy-paste-able notes for your title block.
The below notes are common across CNC drawings — adjust to your standards. Every note that’s ambiguous on your drawing is a question we have to ask before we can quote.
Default tolerances
UNLESS OTHERWISE SPECIFIED: DECIMAL: .X = ±0.030, .XX = ±0.010, .XXX = ±0.005 ANGLE: ±0.5° FRACTIONAL: ±1/64 SURFACE FINISH: 125 µin Ra MAX ALL MACHINED EDGES: BREAK SHARP, ≤0.015 R/CHAMFER
Material callout
MATERIAL: 6061-T651 ALUMINUM PER AMS 4117 CERTIFIED MATERIAL TEST REPORT (CMTR) REQUIRED
Finish callout (anodized aluminum)
FINISH: TYPE II CLASS 2 ANODIZE PER MIL-PRF-8625 THICKNESS: 0.0005-0.0010 INCHES COLOR: BLACK MASK ALL THREADED HOLES AND PRESS-FIT BORES
Finish callout (passivated stainless)
FINISH: PASSIVATE PER AMS 2700 METHOD 2 (CITRIC ACID) ALL DIMENSIONS APPLY AFTER PASSIVATION
GD&T datum scheme
PRIMARY DATUM A: BOTTOM SURFACE SECONDARY DATUM B: BACK SURFACE TERTIARY DATUM C: LEFT SURFACE ALL POSITION TOLERANCES PER ASME Y14.5-2018
Inspection requirements
FIRST ARTICLE INSPECTION REQUIRED PER AS9102 FAI FORMS 1, 2, AND 3 TO ACCOMPANY FIRST SHIPMENT 100% INSPECTION FOR FEATURES MARKED *
ITAR / export control
THIS DRAWING CONTAINS TECHNICAL DATA SUBJECT TO ITAR (22 CFR 120-130). EXPORT, RE-EXPORT, OR DISCLOSURE TO FOREIGN PERSONS WITHOUT PRIOR DDTC AUTHORIZATION IS PROHIBITED.
DFARS specialty metals
ALL SPECIALTY METALS PER DFARS 252.225-7008/9. DOMESTIC MELT, POUR, AND FORGING REQUIRED. ORIGIN CERTIFICATION REQUIRED WITH SHIPMENT.
GD&T frame templates
Common feature control frames.
Position to 3 datums
⌖ ⌀.005 Ⓜ A B C
True position of a feature within 0.005 cylindrical zone, modified at MMC, datums A primary, B secondary, C tertiary.
Flatness on a face
⏥ .002
Surface must lie within two parallel planes 0.002 apart. No datum reference (form tolerance).
Perpendicularity to datum
⊥ ⌀.001 A
Feature axis perpendicular to datum A within a 0.001-diameter cylindrical zone (the ⌀ makes the zone cylindrical). Common on locating features.
Profile of a surface
⌓ .005 A B
Surface shape constrained to a 0.005 zone relative to datums A and B — equal-bilateral (±0.0025) by default; unilateral or unequal distribution requires the Ⓤ modifier.
Total runout
⌰ .002 A
Combined deviation of the entire feature surface as it rotates about datum A axis. Used on shafts.
Concentricity (legacy)
◎ ⌀.005 A
Note: removed from ASME Y14.5-2018 — use total runout or position to specify the same intent.
Revisions
Track every change.
Every released drawing should have a revision block listing every change since release. Revisions are typically lettered (A, B, C, …) starting at A or sometimes at “Initial”. The revision block lives next to the title block, usually in the upper-right.
- ·Letter the revision: A, B, C... (skip I, O, Q, S, X, Z to avoid confusion).
- ·Reference the change: ECN/DCN number tying the rev back to the change order.
- ·Date the change: ISO format YYYY-MM-DD recommended.
- ·Approver initials: Person who released the change.
- ·Description: “Changed material to 6061-T6” — short, clear, action-verb phrasing.
For aerospace/defense work, ECN-controlled drawings are required — every revision tied to a Change Notice document.
Keep exploring
Related tools & references
Every feature-control-frame symbol for your drawing frames.
Default tolerance classes and what to call out where.
Score your drawing against 32 manufacturability checks before release.
The geometry and tolerance decisions that drive part cost.
How to call out a finish unambiguously in your notes.
Drawing's ready? Let's quote it.
Tell us about your part and we'll get back to you promptly. Aerospace, medical, defense, and semiconductor production work welcome.Email CAD models and drawings to sales@digitalmachine.com, including ITAR, EAR, CUI and AS9100 work. Keep controlled technical data out of web forms.
First articles through full production runs