| Business | Phone |
| Ajax Tocco Magnethermic Corp 2525 N Shadeland Ave, Indianapolis 46219 | (317) 352-9880 |
| Circle City Heat Treating Inc 2243 Massachusetts Ave, Indianapolis 46218 | (317) 638-2252 |
| Contour Hardening Inc 8401 Northwest Blvd, Indianapolis 46278 | (317) 876-1530 |
| Exotic Metal Treating 6234 E Hanna Ave, Indianapolis 46203 | (317) 784-8565 |
| Honey Comb Products Inc 405 W Raymond St, Indianapolis 46225 | (317) 787-9351 |
| Indiana Metal Treating Inc 512 S Harding St, Indianapolis 46221 | (317) 636-2421 |
| Sturm Steel 1110 S Drexel Ave, Indianapolis 46203 | (317) 357-2368 |
| Quality Steel Treating Llc 3860 Prospect St, Indianapolis 46203 | (317) 357-8691 |
| Leed Thermal Processing Inc 1718 N Luett Ave, Indianapolis 46222 | (317) 637-5102 |
| Indianpolis Thermal Proc Div 405 W Raymond St, Indianapolis 46225 | (317) 781-4300 |
| Industrial Heat Treating 500 W 21st St, Indianapolis 46202 | (317) 924-4321 |