Glenfern Associates: Gear Ratio

Free Service

We have introduced a free service, which finds pairs of gears that match closely a gear ratio between 1 and 10, subject to a maximum tolerance of ±1.0%.

The results are obtained from pairs with 6 to 200 teeth on the pinion and 6 to 500 teeth on the gear.

Hopefully, you will find it useful; it should give you some idea of what we can offer later.

Access keys (if available) are underlined; also, Alt-F submits a request to find pairs of gears that match the given ratio closely, and Alt-U resets fields to their previous or default values.

e.g. To access the Gear Ratio field, you should press Alt-R if you are browsing with Internet Explorer; with Firefox, you should press Alt-Shift-R instead.

All fields marked with * are mandatory.

Gear Ratio (between 1 and 10) *
Maximum teeth on pinion *
Tolerance *

Gear Ratio = (No. of teeth on Gear) ÷ (No. of teeth on Pinion)

By convention, where the numbers of teeth are unequal, the pinion has the fewer teeth. i.e. Gear Ratio ≥ 1

It is considered better practice to use a compound gear train rather than a pair of gears for ratios greater than 10.

Although, in many cases, several combinations of pairs of teeth have the same (or closely similar) gear ratio, not all of the combinations that are equivalent numerically would be suitable for a given application.