Tolerances (for ANSI Metric standard) dialog box

Specifies the tolerance class and fit class.

Access:

Ribbon: Design tab Power Transmission panel Involute Splines. In the Involute Spline Connection Generator, click next to the Length edit field.

OK

Confirms the selection and closes the dialog box.

Cancel

Closes the dialog box.

Tolerance class

Select the class of the tolerances.

This standard includes four classes of tolerances on space width and tooth thickness to provide a range of tolerances to meet a design need. The classes are variations of the former single tolerance which is now Class 5 and are based on the formulas shown in the footnote of Table 4. All tolerance classes have the same minimum effective space width and maximum effective tooth thickness limits so that a mix of classes between mating parts is possible.

For other tolerance classes:

Class 4 = 0.71 x Tabulated value

Class 5 = As tabulated in table

Class 6 = 1.40 x Tabulated value

Class 7 = 2.00 x Tabulated value

Tolerance class

Select the class of fit.

The Standard provides the same internal minimum effective space width and external maximum effective tooth thickness for all tolerance classes. It is possible to interchange an assembly between mating splines regardless of the tolerance class of the individual members, and permits a tolerance class "mix" of mating members. This arrangement is often an advantage when one member is considerably less difficult to produce than its mate, and the "average" tolerance applied to the two units is such that it satisfies the design need. For example, by specifying Class 5 tolerance for one member and Class 7 for its mate, an assembly tolerance in the Class 6 range is provided.

Fit Classes: Four classes of side fit splines are provided: spline fit class H/ h having a minimum effective clearance, c v = es = 0; classes H/ f, H/ e, and H/ d having tooth thickness modifications, es , of f, e, and d, respectively, to provide progressively greater effective clearance c v . The tooth thickness modifications h, f, e, and d are fundamental deviations selected from ISO R286, "ISO System of Limits and Fits." They are applied to the external spline by shifting the tooth thickness total tolerance below the basic tooth thickness by the amount of the tooth thickness modification to provide a prescribed minimum effective clearance c v .

Design Tab