Diameter Sign Symbol
The ⌀ symbol (DIAMETER SIGN) indicates diameter in technical text, drawings, and specifications.
U+2300
The ⌀ character is the Unicode Diameter Sign (U+2300). It’s commonly used in technical writing and diagrams to specify the diameter of circles and cylindrical parts. You can copy it directly or insert it using Unicode escapes in code.
Diameter Sign Symbol Meaning
⌀ (DIAMETER SIGN, U+2300) is a technical symbol used to denote diameter. It’s frequently seen in engineering notes, machining instructions, and dimension callouts where a circle’s size must be specified clearly and compactly. In practice, ⌀ is typically followed by a measurement (for example, “⌀10”) to indicate the diameter of a hole, shaft, or round feature. Because it’s a dedicated Unicode character (rather than a plain “D”), it helps maintain consistent typography and improves readability in CAD-related text, specs, labels, and documentation.
Common uses
- •Labeling the diameter of holes or bores in engineering documentation
- •Specifying shaft or pin diameters in machining and parts lists
- •Annotating round features on technical drawings and dimension notes
- •Writing measurement callouts in datasheets and manufacturing instructions
- •Designing UI/print templates for technical specs that require diameter notation
Examples
⌀ Diameter Sign (U+2300)
- ⌀Hole size: ⌀8
- ⌀Drill to diameter ⌀12 mm
- ⌀Pin: ⌀5 (tolerance ±0.02)
- ⌀Counterbore: ⌀20.0
- ⌀Shaft diameter ⌀25
Variations
Ready to copy
Technical codes
| Unicode | U+2300 | |
| HTML Entity | ⌀ | |
| HTML Code | ⌀ | |
| CSS | \2300 |
FAQ
What does the symbol ⌀ mean?
⌀ is the Diameter Sign. It indicates diameter, usually followed by a measurement (e.g., ⌀10 mm).
What is the Unicode code point for ⌀?
The Unicode code point for ⌀ (DIAMETER SIGN) is U+2300.
How can I copy ⌀ for use in text or design tools?
You can copy the character directly from this page, or use the HTML entity (⌀) or the escapes shown in the copy variations.
Is ⌀ different from the letter “D” or the “Ø” character?
Yes. ⌀ is the specific Unicode DIAMETER SIGN (U+2300). It’s intended for diameter notation in technical contexts.