Here is a general bidding rule ive used for things you cant plug into the bid by quanities because its just not practicle like nuts, bolts, washers, blades, tool maintenence and usage, tape, pulling lube, broken snake heads during pulls,and non productive labor (walk throughs, job meetings, etc.. try 2.5% to 3% of every gross estimate and compare it to your actual cost on a couple of jobs and let me know what you think. there isnt a profit in that percentage but it covers your cost pretty good.
