| Business | Phone |
| Bulaw Welding & Engineering 2434 W Fletcher St, Chicago 60618 | (773) 929-3322 |
| Alloy Concepts Inc 1301 N Dearborn St, Chicago 60610 | (312) 335-0900 |
| General Surface Hardening Inc 2108 W Fulton St, Chicago 60612 | (312) 226-5472 |
| Chicago Induction Metal Treat 3305 W Harrison St, Chicago 60624 | (773) 826-1213 |