View Full Version : Steel Selection

04-24-2009, 06:52 AM
Im quoting on building a new shaft for a severe duty hydraulic pump.....The old shaft was hardened but the woodruff keyslots failed. The OD of this shaft is also used as a bearing surface for roller or needle bearings....Any thoughts on which steel to use & hardness reccomendations?.....Jerry

Don Wojtaszek
04-24-2009, 08:29 AM
Try induction hardened 4340 or case hardened 4120. Both will have to be ground and hard chromed.

Good luck!

04-24-2009, 10:16 AM
Would there be any benefit in replacing the Woodruff key with a cylindrical one? Duffy

04-24-2009, 10:57 AM
I'm with Duffy here - the problem is that the surface of the shaft has to be very hard for the needle bearings to run without brinelling, but that very hardness with the cut slot for the Woodruff key gives rise to stress fractures. Maybe a taper hub mount instead of the keyed mount?

04-24-2009, 12:04 PM
Why not repair the shaft they have if it's not bent. Weld the old key way up turn ID smooth... rotate 180 and cut new key slot. Quick turn around and you gain a customer by saving them money while still making some for your shop. ;)

04-25-2009, 06:20 AM
Thank you all for your input.....lots of good information....Jerry