| Business | Phone |
| Safety Socket Screw Corp 6479 N Avondale Ave, Chicago 60631 | (773) 763-2020 |
| V & W Machining 1744 W Winona St, Chicago 60640 | (773) 769-0450 |
| National Washer Corp 2215 W Wabansia Ave, Chicago 60647 | (773) 772-6214 |
| Skohm Products Co 1347 W Belmont Ave, Chicago 60657 | (773) 281-6464 |