Mark's Locksmith
| Mac Tools | toolbox | 1605 |
| Mack trucks | pre-cut | DAV10 |
| Mag | patio door | AGE2, A191 (Taylor) |
| Magic Eye | 999 | |
| Magnum | padlock | 1092D |
| Mag wheel lock | 1127ES, 1041T, O1122 | |
| Mailboxes | See name brand | |
| Markon | 1069N | |
| Mark | 999 | |
| Marks | 1179, 1145 | |
| Marlette | RV | 1054WB |
| Master | padlocks | See Ilco #60 |
| Mastercraft | tool box | 1054UN |
| McDowell Craig | O1122 | |
| McGunn | safe | BD551 |
| Medalist | R1064E, 1069N | |
| Medart | 1326, 1332, 1332S | |
| Medeco | restricted, plus: | 1515, A1515, 1517, A1517, 1518, 1542, 1543 |
| Melex | golf cart | OKB12 |
| Mercury | outboard motors | See Ilco #60 |
| Meroni | furniture locks | MER2, MER23, MER24 |
| Mer-Pel | vending | OKB159 |
| Metal vent | 1022 | |
| Metal-Rousseau | MR1, MR2, M64 | |
| Micro-Switch USA | HV61 | |
| Mister Minute | 999 | |
| Mitchell | 1041T | |
| MMF | 1041T, O1122 | |
| Mobella | OKB6, BDK6R | |
| Moleba | O1122, O1122A | |
| Monarch | X1054K | |
| Monterey | O1122 | |
| Montgomery Ward | freezers | 1069N |
| Mortise | Sears lock sets | 1092N |
| Moss | 1145, 1054K, D1054K, 1176 | |
| Moto Ski | O1122, O1122A | |
| Multi-Lock 1022 | 1022 |