First-angle projection symbol

A truncated cone shown in two views, stating which projection convention a drawing uses.

Also known as: European projection symbol, Cone symbol on a drawing

Engineering & technicalStandard profile

Meanings

This symbol exists because two incompatible conventions are in use: first-angle in Europe, third-angle in North America. A drawing read under the wrong one has its views on the wrong sides, and the parts come out mirrored.

Common modern usageVerified fact
States that the drawing's views are arranged by first-angle projection, in which each view is placed on the side away from the observer.
Contexts: Technical drawing
Common modern usageVerified fact
Exists because first-angle and third-angle projection are both in wide use and produce arrangements that are mirror images of each other, so a drawing without the symbol is genuinely ambiguous.
Contexts: Technical drawing
Common modern usageVerified fact
Is governed by ISO 128, which sets out the presentation conventions of technical drawings.
Contexts: Technical drawing

Visual description

A truncated cone drawn in side view as a trapezoid, beside its end view drawn as two concentric circles, with the circles placed to the left of the trapezoid.

Symmetry: horizontal
Orientation: upright

Commonly confused with: Third-angle projection symbol
The symbols are mirror images and are read at a glance, which is exactly when a mirror image is missed.
Opposite of: Third-angle projection symbol
The two conventions arrange views on opposite sides; the symbols are mirror images.

Compare: First-angle vs third-angle projection →

Confidence

IdentityHigh confidence: High confidence because the identity is documented in encyclopedic references, but multiple independent sources agree.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, but multiple independent sources agree, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is documented in encyclopedic references, but multiple independent sources agree.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references, but multiple independent sources agree.

Sources

ISO 128, Technical drawings — General principles of presentation
International Organization for Standardization · retrieved 2026-08-01
Paywalled and NOT READ. Registered so records can state which standard governs a symbol — a checkable fact a reader can act on — and for nothing else. It governs line types, views, sections and projection conventions. No meaning in any record is typed `official` on the strength of this entry. See docs/paywalled-standards.md.
Multiview orthographic projection
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for what a symbol instructs and which standard governs it. Where a standard is named it is reported by this source rather than read, so no meaning is typed `official` on that basis.
Technical drawing
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for what a symbol instructs and which standard governs it. Where a standard is named it is reported by this source rather than read, so no meaning is typed `official` on that basis.

Last reviewed 2026-07-31

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Technical drawing notation

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Meanings

Common modern usageVerified fact

States that the drawing's views are arranged by first-angle projection, in which each view is placed on the side away from the observer.

Contexts: Technical drawing

Common modern usageVerified fact

Exists because first-angle and third-angle projection are both in wide use and produce arrangements that are mirror images of each other, so a drawing without the symbol is genuinely ambiguous.

Contexts: Technical drawing

Common modern usageVerified fact

Is governed by ISO 128, which sets out the presentation conventions of technical drawings.

Contexts: Technical drawing

Related & commonly confused symbols

Commonly confused with: Third-angle projection symbol
The symbols are mirror images and are read at a glance, which is exactly when a mirror image is missed.
Opposite of: Third-angle projection symbol
The two conventions arrange views on opposite sides; the symbols are mirror images.

Confidence

IdentityHigh confidence: High confidence because the identity is documented in encyclopedic references, but multiple independent sources agree.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, but multiple independent sources agree, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is documented in encyclopedic references, but multiple independent sources agree.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references, but multiple independent sources agree.

Sources

ISO 128, Technical drawings — General principles of presentation
International Organization for Standardization · retrieved 2026-08-01
Paywalled and NOT READ. Registered so records can state which standard governs a symbol — a checkable fact a reader can act on — and for nothing else. It governs line types, views, sections and projection conventions. No meaning in any record is typed `official` on the strength of this entry. See docs/paywalled-standards.md.
Multiview orthographic projection
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for what a symbol instructs and which standard governs it. Where a standard is named it is reported by this source rather than read, so no meaning is typed `official` on that basis.
Technical drawing
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for what a symbol instructs and which standard governs it. Where a standard is named it is reported by this source rather than read, so no meaning is typed `official` on that basis.

Last reviewed 2026-07-31