If the anchor bolts installed too low in concrete or steel plate, it means that there would be not enough thread length projected to secure the anchor bolt to base plate or steel plate, so, in this case , one of the solutions to solve this issue is to use “Elocone Nut” .
These special nuts can be ordered and produced in hot-dip galvanized finish as well. These nuts look like reverse shape of regular bolt and nut connections, since the thinner (bottom) part would go to be screwed to short length of existing projected anchor bolt (projected from base plate or steel plate).
As general note and based on Handbook of Steel Construction (CISC):
Please Note that the certain A325 Bolt maybe ordered in Threaded Full Length which is permitted under Supplementary Requirement S1 of ASTM A325.
They are restricted to bolts with nominal lengths no greater than four times the nominal diameter.
To use proper size and number of these nuts, please consult with structural engineer.