Spherical Diameter

Indicates the diameter value applies to a spherical feature.

S⌀

3.00

Spherical diameter modifies the diameter symbol to show the feature is spherical, not merely circular.

The symbol is shown before the size dimension.

Use it for balls, spherical seats, domes, or other features controlled by a full sphere diameter.

Use spherical radius when the design intent is better expressed from the center to the surface.

Spherical Diameter Drawing Use

Spherical Diameter is read with the adjacent dimension, note, or feature control frame so inspection uses the intended feature definition.

\u25cb

0.04

This symbol defines or modifies a size, shape, or manufacturing dimension rather than creating a GD&T tolerance zone by itself.

Read the symbol with the attached dimension, note, or feature control frame before evaluating the feature.

Verify the controlled feature using the drawing's stated limits, datum setup, and any special notes tied to the symbol.

A drawing includes the Spherical Diameter symbol with a related feature requirement.

Identify

S⌀

Recognize the Spherical Diameter symbol and the feature it modifies.

Read

Adjacent value

Use the attached dimension, note, or frame cells as the controlling requirement.

Inspect

Per drawing

Measure the named feature using the specified interpretation rather than assuming a generic size check.

Spherical Diameter clarifies how the feature is defined so the drawing and inspection method stay aligned.

Item	Controls	Typical Placement
Spherical Diameter	Dimension interpretation	Next to a dimension, note, or frame
GD&T control	Geometric variation	Feature control frame
Datum reference	Measurement setup	Datum feature or frame cell

This page is part of the drawing-symbol reference set rather than a standalone geometric tolerance category.

When the symbol modifies a feature control frame, read it together with the tolerance value and datum references.