What ⌵ means
It specifies a cone-shaped seat around a hole. A screw, bolt, or rivet head can sit flush with or below the face. On a drawing, this symbol precedes the recess dimensions.
ASME Y14.5M-1994 places the symbol before its dimensions; ASME Y14.5-2018 retains the callout. ISO 5845-2:1995 uses an oriented triangle in a quadrant to show which side of riveted parts is countersunk.
What it means when someone sends it to you
2 readingsASME Y14.5-2018 hole callout
Place ⌵ before measurements such as the recess diameter and included angle.
ISO 5845-2 countersink notation for rivets
An oriented triangle in a quadrant shows which side of the riveted parts is countersunk.
Don't confuse it with
1Questions people ask
1Why does the countersink symbol look different in my font?
It can vary: fonts draw this text glyph differently, so a plain V shape may look like a downward angle. The drawing callout supplies its meaning.
How to type ⌵
Windows (Word)
Alt+XType 2335, then Alt+X to get ⌵.
Windows
Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win + .).
macOS
Control+Command+SpaceOpen the character viewer and search “countersink”.
Linux
Ctrl+Shift+UType 2335, then Enter or Space.
HTML
⌵CSS
\2335Codes and encoding1 code points
HTML decimal
⌵
HTML hex
⌵
CSS content
content: "\2335";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%8C%B5
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.