When not working under Parts 121, 135, or 145, you are not required to show compliance with calibration, except where specifically called out. However, how are you going to show that you did the work to a known value, if your tools aren't calibrated?
If you use an uncalibrated tool to torque a part which requires 40-50 inch-lbs, how can you show you performed it (or be sure you did) to that value unless the tool has a current calibration? Same for electrical measurements, etc. Calibration isn't just about doing the job properly, either...it's for your own protection with respect to the liability of ensuring the job is done correctly.