The default friction values are suitable for non lubricated steel bolts.
The calculated values (at the top of the calculator, in red) are the maximum recommended values, based on 90% of yield. If you want to know the torque needed to generate a lower load, vary the Yield parameter until the desired load appears. The corresponding torque can then be read out.
Please notify Norbar of any enhancements or corrections you would like to see made to our calculator!