That goes for firearm accessories and ammunition, as well, purchased by city departments and sister agencies.
The order, gun violence prevention advocates say, will add public safety and accountability measures to the city's evaluation of firearm vendors, helping ensure public dollars support lawful business practices and stronger industry accountability.
Proponents of the measure, like Live Free Illinois, have been pushing the idea for years.
They say cities don't have to wait on other levels of government to act, they can use their own contracts, standards, and taxpayer dollars to demand responsibility from the firearms industry themselves.
The signing is expected to take place at 9 a.m.