[monte55]

I have a drive shaft which at least the splined ends are hardened and possibly
the entire shaft. The shaft is .701" in diameter. I would like to drill a 3/8" hole through the side of the shaft and have a 3/8" grade 8 bolt through the shaft.
My question is: Is the bolt stronger than the material left on the shaft after
boring the 3/8" hole. I don't want any larger than 3/8" bolt but do I need to be smaller? The bolt or pin will not really see any tension stress but more shear. There will be a small bearing on each side of the bolt riding in a channel inside another piece of round stock. I am making a slip joint.
Nick

[keebler303]

After you drill the hole, the shaft will probably fail before the bolt does. The shaft will have less material left and will have a large stress concentration from the hole. The question is how strong does it need to be?

I don't know what you are trying to do but you can buy splined components from several online sources.

http://sdp-si.com/web/html/newprdshafts2.htm

You can also salvage this type of thing from the driveshafts of most rear wheel drive cars and trucks.

Matt