Thread callout

What the annotation identifies#

A thread callout records the thread definition needed to manufacture or inspect a threaded feature. The exact fields and syntax depend on the governing thread and drawing standard, but the definition commonly includes the nominal designation, pitch or threads per inch, class, handedness when non-default, and depth or extent.

Onshape's Hole documentation stores tapped-hole size, pitch or threads per inch, optional class, and tapped depth in the feature. Its hole/thread callout can then annotate that feature in a drawing. Onshape's separate External Thread feature supports the same callout workflow for a threaded shaft or boss.

Why the callout matters#

The shaded model does not communicate a complete thread requirement. A smooth cylinder may carry a valid cosmetic thread, while a helical solid may still omit the intended class or usable depth. The callout makes the requirement visible to manufacturing and inspection without asking them to reverse-engineer it from nominal geometry.

SOLIDWORKS Design Help 2026 links cosmetic-thread features with drawing callouts and explains that the representation can be inserted into drawing views. An associative callout reduces manual duplication, but it still needs to be checked against the mating part and the governing standard.

Keep it tied to the released feature#

A manually typed note can disagree with the model after a thread size or depth changes. Prefer a callout associated with the hole or thread feature, then verify the resulting text in the released drawing or PMI.

Neutral CAD exchange may not preserve the native feature or annotation in a form the receiver can use. Confirm the actual export and include the controlled drawing or PMI whenever the thread specification is required downstream.