| Business | Phone |
| Anderson Heat Treating Inc 1241 18th Ave, Rockford 61104 | (815) 968-0094 |
| Beavermatic Inc 424 Buckbee St, Rockford 61104 | (815) 963-0005 |
| Beechner Heat Treating Co Inc 905 Brooke Rd, Rockford 61109 | (815) 397-4314 |
| Regal Products Inc 4462 11th St, Rockford 61109 | (815) 387-2162 |
| Rock River Heat Treating Co 5136 27th Ave, Rockford 61109 | (815) 397-5424 |
| Rockford Heat Treaters 4704 American Rd, Rockford 61109 | (815) 398-6533 |
| Diamond Heat Treat 3691 Publishers Dr, Rockford 61109 | (815) 873-1348 |
| Material Technologies Inc 5240 American Rd, Rockford 61109 | (815) 874-1717 |