Model Engine Company of America
Finding a thread pitch on an unusual size.

Thread pitch is measured by number of threads per inch or mm

No mater the diameter, the size of the pitch is always the same. For instance you can have a 6-32 thread, 6 being the diameter (threads under 1/4" diameter are called out by numbers i.e.: 2, 4, 6, 8, 10 etc.) and 32 being how many threads per inch. So a 6-32 thread is the same size in height as a 1/2"-32 or on a 1"-32

In Metric, pitch and size by millimeter. So a common screw on a model engine is 3x.5 , 3 mm diameter and .5 pitch, so have a thread per mm.

In other words for inches a 32 pitch thread would take 32 turns to move 1 inch. In metric a .5 pitch would take 2 turns to move 1 millimeter.

Easy way to find the pitch you have.
Find a screw with a pitch you know. For this example we will use a common 4-40 screw to check the thread pitch on a spraybar.
The screw threads should mesh perfectly. If not find another screw with a different pitch. i.e.: 6-32 10-24 1/4-28 etc.

You should be able to find a perfect match.

Unless you are checking a metric thread with an American SAE screw.

The above information is provided as a guide. Since MECOA/K&B has no way of determining the ability of the individual using and understanding this information, we assume absolutely NO RESPONSIBILITY for any damage to person or property from the use of this information.