Mark's Locksmith
| Taco | padlock | 999, 999A |
| Taxi | padlock | 1098M |
| Taynor | 999 | |
| Tegco | TG1, 1013BF, 1014F, X1014L | |
| Teknion | 1502 | |
| Telco | 1022, 999 | |
| Testa | 1092 | |
| Thermostats | 1541 | |
| Thule | ski racks | LF12 Silca, X132 |
| Thunderbird | boat | O1122 |
| Timberline | office furniture | 1043J, OKB84, OKB126 |
| Tire locks | 997E, O1122, 1041Y, K1122D, O1122A | |
| Tire locks | DM110, DM63, GE33, GE10 | |
| Titan | 6-pin Kwikset | |
| Tofco | 1069W | |
| Tok | 997E | |
| Tool box | Sears | 1041T, R1096EN |
| Topper | RV | O1122A |
| Topps | freezer | 62FS |
| Tower | 1000F, X1000FR, 192 | |
| Tractor, Ford | 1569, 1570 | |
| Tractors | Ignition pre-cuts | |
| Travco | padlock | 1000V |
| Trelock | 1092, 1092B | |
| Trey | 1176 | |
| Triangle | 1022, 997E | |
| Tri/Mark | RV, toolbox | TM1 to TM4, TM6 to TM10, TM12 to TM15, OKB157, OKB163, OKB64 |
| Trimguard | 1179 | |
| Trojan | boat | L1003M |
| Trojan | 1176 | |
| Trovill | RV | P1098A, 1970AM, H1098X |
| Troy | 1176 | |
| Tuberlite | 1004, 1004A | |
| Tuftest | 1022, 999 | |
| Tundra | O1122, O1122A |