Is there any common sizes or nominal dimensions for splines? Is an Involuted spline the optimum design for a spline? Is there any websites have information on splines that may be helpful?
wheeln
Splines ARE standardized.
Here are some involute spline standards:
ISO4156, DIN5480, ANSI B92.2M (all metric, module based splines; metric spline standards are practically all the same) or ANSI B92.1 (US,inch, diametral pitch based standard).
How about generating your own spline? I used the following for a fridge ice crusher application. The gear is HT PM with an ID made up of 30-40 semicircular lobes. The mating shaft has a collar such that the shaft clears the lobular ID of the gear. At assy, with mating parts aligned carefully, the gear broaches the shaft, and you now have an intimate rounded spline assy.
The alternative is expensive: precision outer part mating with precision inner part with all the tolerancing challenges that go with it.