What is gear pitch?

It has to do with the size of the tooth. Others will chime in and give you way more than you will ever need to know. WWQ

Pitch is the distance between teeth. There is diametral pitch for English, and metric module pitch for metric. Now the teeth are arranged on a circle so that the tips are farther apart than the roots so you have to clarify where on the tooth you're measuring. Typically we say that the pitch circle is where the pitch is measured. The pitch circle is about halfway between the tips and the roots. For diametral pitch, the # means how many teeth will fit on a pitch circle of 1" diameter. For metric module, it is the arc distance x Pi along the pitch circle from one tooth to the next.

So, a 16DP gear with 32 teeth has a pitch circle of exactly 2" diameter. If you "straightened out" the gear, the teeth would be 1/16" x Pi apart.

A 2mm metric module gear with 32 teeth has a pitch circle of exactly 64mm diameter. If you straightened this gear out, the teeth would be 2mm x Pi apart.

There are a gazillion other parameters and formulas for the rest of the gear form.

Regards.

Finegrain

Depends on which pitch you mean

The diametral pitch (abbreviated P or d.p.) is the ratio of the total number of teeth on the gear to the pitch diameter, expressed as teeth per inch. If you have gears with a diametral pitch of 12, a 12-tooth gear will have a pitch diameter of 1", while a 24-tooth gear will have a p.d. of 2".

The circular pitch (p) is the distance along the pitch diameter from the face of one tooth to the corresponding face of an adjacent tooth.

- Leigh

Ref: Boston Gear catalog, Engineering Information section, page 134.

In Imperial jargon, it is Diametral Pitch, which equates to how many teeth can be put on a gear with a 1.0000" pitch diameter.

A little different in the metric world, where it is simply Module and equates to again how may teeth can fit on what pitch diameter, but in a different way.

I.E., if I can get 20 teeth on a 40mm pitch diameter, the tooth size is said to be 2 Module. If I can only get five teeth on that same 40mm P.D., it is 8 Module

John Oder