Embodiments include a disk drive having a drive motor assembly including at least one component selected from the group consisting of a rotatable hub, disk spacer, disk clamp, backiron, lower bearing bushing, and lower mounting flange. At least one of the components comprises a low sulfur outgassing free machining stainless steel material. The low sulfur outgassing free machining stainless steel material may include a free machining stainless steel that outgases sulfur at a rate insufficient to cause visually observable sulfide corrosion when tested by placing a copper strip into contact with the free machining stainless steel in an environment having a temperature of 50.degree. C. and 90% relative humidity for a 7 day test period and then observing the copper strip.
A non-reactive hard coating of carbon or ceramic is applied to the major components of the spindle motor which are exposed to the atmosphere internal to the hard disc drive. By having such a thin layer of carbon or other ceramic coating, it will protect against outgassing of motor components and create a neutral or non-reactive surface that does not promote corrosion. The coating thickness can be preferably in the order of nanometers to microns depending upon the drive design and the operating conditions.
