please don't double post

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P.E. Metallurgy, consulting work welcomed

Sure, wasn't sure which one was the most appropriate section

SAE, ISO, and DIN all have standardized spline forms with supporting application notes. Poor lubrication conditions will add application specific challenges.

The SAE standard is J499, my copy is elsewhere at the moment. https://www.sae.org/publications/technical-papers/... is also relevant

Cheers

Greg Locock


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Sorry but both of those are not this type.
J499 is parallel sides and 510206 involute splines.

The ones i am talking about are serrated splines cut with a standard lathe cutting tool (usually 90 degrees but could be any angle you want technically if you match the coupling)

See the difference here (edit, not very clear between involute and serrated, serrated can still have less teeth so there is no need for each tooth to follow the immediate one after, involute is defined by the involute tooth profile that cannot be observed by the photo):



Here's a better section but still not 100% accurate:




Also here are some videos showing how they are cut:

https://www.youtube.com/watch?v=vxCV4TGGKls

https://www.youtube.com/watch?v=10Y6W15fOms

https://www.youtube.com/watch?v=xPZ7hzLdgyU

https://www.youtube.com/watch?v=qTOSgI2bgxk

This type is the most commonly used spline because it's cheap and easy to make. Also it's probably better than the straight/parallel-sides spline because of less stress concentration and higher torque capacity, however this type is generally found in most agriculture PTO equipment still (probably due to legacy compatibility with older attachments)

Here's the exact type of this spline. I quickly modeled it. Attached step file.

• https://files.engineering.com/getfile.aspx?folder=b83c8660-8bbd-4a97-981d-a

BS 2059 seems to cover serrated splines. I'd have thought a rolled spline would be far more satisfactory than a cut one.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Yes it's done on mass production with this knurling machine since you need different dies depending on the tooth size: https://www.youtube.com/watch?v=HJhCy5VH7
BS 2059:1953 does indeed cover serrated splines of the same profile ( https://idoc.pub/documents/bs-2059-1953-en5k7j396x... )

The linked video is gone.

https://www.youtube.com/watch?v=HJhCy5VH7uI

Looks i've mistyped it

I work with aircraft applications, but all three type of splines are used. how ever 45 deg, splines are a pita. I prefer involute splines.
45 deg splines change on size with any post operations.

Yes involute is the ideal spline form but requires special tooling to cut, that's why it's not as common especially for coupling splines. However it's very common in gear teeth.

Not strictly true. A rack with the correct straight flanked teeth will cut an involute into a shaft if it is progressively fed across as the shaft is rotated. You wouldn't do it that way by choice, but that's how it would have been done once upon a time

http://david.rysdam.org/machining/gears.html

Thinking about oit an easier way would be to use a cutter with straight flanks, and put the shaft on the bed of the milling machine. I think that's how i did it at college

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Storm33

30 degree spline are very common.
for high volume spline rolling, for moderate production spline hobbing and shaping , low to high volume spline grinding. I mostly work with mostly ANSI B92.i, again aircraft applications.
if the parts are high volume the tooling is relative inexpensive because the tooling is amortized by quantity of parts. the required quality and runout required will dictate the machining method.