| Business | Phone |
| Prevue Metal Products Inc 224 N Maplewood Ave, Chicago 60612 | (312) 243-3624 |
| United Sources Inc 7401 S Pulaski Rd J, Chicago 60629 | (773) 284-8600 |
| O & K American Corp 4630 W 54th St, Chicago 60632 | (773) 767-2500 |
| Willdon Corp 4500 W Division St, Chicago 60651 | (773) 276-7081 |