I'm working on sending a drawing of a spline to a gear manufacturing company in my area. However, they need to know the pressure angle of said spline. The size is standard (5/8" 36) but I can't seem to find any literature which gives the pressure angle of such a spline. Any suggestions for where to look? I know that a lot of places sell 5/8" 36 shafts, but it's cheaper for me to buy 5/8" round stock and send it to this manufacturer (I'm on a racing team and we have a sponsorship with them), so I would like to know the exact angle.