Involute spline shaft gearing

Hello everyone,


During a project an oil pump shaft broke off and we were able to re-order most of the standard parts from the OEM. However, the shaft with an involute spline has to be manufactured. The workshop is now asking us for a .dxf of a section of the involute spline.

I work as an engineer in the energy sector and my experience with involute spline gearing is very limited (never worked with before).


The OEM drawing of the oil pump indicates the involute spline as the following (also see attached image):

16/32 Involute spline
15 tooth flat root, side fit.
Over .120 dia. pins = 1.081/1.082

Outer dia of the involute spline: 0.9825/0.9835

Is it possible to determine by the above information if this gearing is acc. to a standard? We don't own software for gearing, so if anyone could help, that'd be greatly appreciated.


Thank you.

Your drawing is unreadable. Can you post it in as larger image?

I'm not familiar with involute splines, but I've done a bit of involute gears and two defining characteristics are the "diametrical pitch" (or "module" which is the reciprocal much like SAE v. metric in screw pitches) and the "pressure angle". If you know those and the number of teeth, everything else falls into place. It may be possible to deduce these from your measurements above or there may be more info in your drawing.

pantrofl said:

16/32 Involute spline
15 tooth flat root, side fit.
Over .120 dia. pins = 1.081/1.082

Outer dia of the involute spline: 0.9825/0.9835

Click to expand...

That's all the info you need. Stick it in the hobber and cut it. No idea why anyone would want a dxf for that.

Hi, thanks for the replies.

Larger image can be found here: 2020-12-16-09-12-44-19-10036-pdf-Adobe-Acrobat-Reader-DC — ImgBB

@EmanuelGoldstein: That's good to know. We're also not sure why we have to supply a DXF to a gearing workshop. But if the given information on the drawing is enough for them to manufacture the new shaft for us, then I won't bother with the DXF. Seems like supplying a DXF on involute splines while our experience is very limited with this technique seems like we're asking for something to go wrong.

Thanks again.