This is pretty basic, but how do you guys take care of your holders? I have some fretting going on some very "new" holders with less than 15 hours on them (been through lots a few tool changes though maybe 50-100). What i mean by fretting is around the large end of the taper theres copper coloured marks that look almost like corrosion. I'm not sure if this is a maintenance problem by me or a machine issue. They sometimes seem to stick in the spindle a bit when changing. I showed our service guy and he said you should put light oil on them??? i thought they should be spotless and dry? Is brake or contact cleaner to harsh? Also the tool changes become stickier than normal after heavier cuts, does this sound like a drawbar issue? Its a CAT40 taper in a Milltronics RH
Keep them clean, especially make sure you clean of the residue from coolant drying on them, and oil them with a light oil.
It is okay to use just about any solvent. I clean off coolant residue with alcohol and oil residue with Varsol. Brake or contac cleaner will be fine.
You are always going to get some fretting but if these holders have not been used very much and it is really noticeable it could mean your drawbar tension is too low. The belleville spring washers that retract the drawbar sometimes break and then the tension is lost. You should see if you can get someone to measure the tension. For Cat40 I think it should be around 1500lbs but I am not positivre about that.
An open mind is a virtue...so long as all the common sense has not leaked out.