Angularity (∠)
Angularity (∠) is an orientation tolerance: a surface or axis meant to sit at a stated angle to a datum has to lie in a zone tilted to exactly that angle. It needs a datum.
Easily confused with
How to read it
The symbol is two lines meeting at an acute angle. The National Physical Laboratory’s guide defines angularity as the condition of a surface or axis at a specified angle, other than 90°, from a datum plane or axis, and the zone as two parallel planes at that basic angle to the datum. The angle itself is a basic dimension, exact and boxed; the tolerance in the frame is a width. Cogorno’s course guide explains why: a linear tolerance gives a zone of even width, where a plus-or-minus angle would give a fan-shaped one. Berez groups angularity with Parallelism (∥) and Perpendicularity (⟂) as the orientation controls of ASME Y14.5-2018, covering 0°, 90° and any other angle to a datum, and all three need one.
Also searched as: ∠, angularity gd&t, angularity symbol.
This explains what a symbol specifies on a drawing. It isn't inspection or design guidance; the drawing and the edition of the standard it cites take precedence.
Look-alikes
The same mark is geometry’s angle sign ∠, which Unicode encodes as U+2220 ANGLE; in a feature control frame, it is the angularity characteristic. For a right angle, a drawing uses perpendicularity ⟂ instead, and for 0°, Parallelism (∥) ∥.
Read next
- Next in GD&T symbolsPerpendicularity (⟂)Perpendicularity (⟂), also called squareness, is an orientation tolerance: a surface, axis or centre plane meant to be at 90° to a datum has to lie in a zone set exactly square to it.
- The same shape in Road signsEdge lineA solid line along the edge of the roadway: white on the right-hand edge, and yellow on the left-hand edge of a divided highway, one-way street or ramp.
More GD&T symbols
The same shape elsewhere
Browse symbols drawn with lines.
Sources
- Fundamental Good Practice in the Design and Interpretation of Engineering Drawings for Measurement Processes, Measurement Good Practice Guide No. 79, David Flack and Keith Bevan, 2005, National Physical Laboratory (UK), Chapter 4, Tolerances of orientation
- Fundamentals of Geometric Dimensioning and Tolerancing (GD&T), Part I, Jaime Berez, seminar adapted from an undergraduate mechanical engineering course, version 2.1.0, 2023, Center for Precision Metrology, University of North Carolina at Charlotte (Zenodo), Slide 32
- Geometric Dimensioning and Tolerancing for Mechanical Design: Instructors’ Guide, Gene R. Cogorno, guide to the McGraw-Hill textbook, rev. 10/12/2020, Technical Training Consultants, Chapter 6, Orientation, review answers
- Mathematical Operators: Range 2200–22FF (code chart), The Unicode Standard, Version 18.0, Unicode Consortium, U+2220
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 10, 2026. How we research
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