Material for making replacement spindle sander spindles

[oliverarn]

I need to make some spindles for my oscillating spindle sanders. The Sander end is #2 Morse with a 1"step at the upper end of the Morse taper. The ones that take a rubber drum are 3/4" od. Smaller ones below 3/8" appear to be hardened rods pressed into the morse taper.
I am not equipped to perform any heat treatment or grinding. I understand that the spindle will gall the machines morse socket if an incorrect steel is used. I have a taper attachment on my lathe.
Thanks in advance.

 

[Dan from Oakland]

4140 Heat Treated would be my 1st choice. Not sure where the galling thing came from, but I would never give that a 2nd thought regardless of the spindle material.

 

[Bill D]

Re; galling do not use any key in the morse taper portion. It is not needed for torque and if it slips it will cause galling. The key is only so it stays in place to tighten the nut.
How will you get the rubber covers made?
BilLD

 

[???]

4340 heat treated machines well at 38 HRC and has better through hardening than 4140.

 

[Dave G.]

Another good choice is ASTM A311: 1141 or 1144 also known as Stress Proof.

It's plenty strong and machines well due to the sulfur addition. It's also stress relieved so should be stable during machining

Not my preference but just plan old 1045, 1045H, or 1050 will also work just fine for spindles. Cold draw is better because it's stronger, but hot rolled will likely be fine.

 

[oliverarn]

Re; galling do not use any key in the morse taper portion. It is not needed for torque and if it slips it will cause galling. The key is only so it stays in place to tighten the nut.
How will you get the rubber covers made?
BilLD

Rubber drums can be purchased. The price is not too bad likely China.
No key just friction fit. Thanks for the response

 

[oliverarn]

4140 Heat Treated would be my 1st choice. Not sure where the galling thing came from, but I would never give that a 2nd thought regardless of the spindle material.

The galling comes from the Spindles slipping in the socket under load. They do not have a key so its just friction fit. Thank you for the response.

 

[richard newman]

+1 for 4140 HT. Used it to make insert spindles for a big German woodworking shaper, 5MT taper on end. Easy enuf to machine, stable, and so far no problems.