Java "Double" inacurancy

I wrote an application recently to calculate measurements for rebuilding an engine. The measurements must be accurate to the tenths thousands of an inch (0.0001 inch).
What I found out, that the standard floating point (double length) operations in Java are extremely inaccurate rendering my program useless for practical purposes.
Of course I can round off the results to one decimal point before and get it accurate enough, but the fact that $2.00 calculator is more accurate than $4,500.00 Apple G4 just upsets me.