| 1 : Foundry's trademark List of foundry symbols and trademarks (PDF 806 Ko) |
2 : Part number (nomenclature) | 3 : Part serial number | 4 : Believed to be either the pattern number of the mold or the location of the plant ("E" could indicate that the part was cast at the Eddystone plant of General Steel Castings) |
| 5 : "LO" is a type of steel particulary adapted to cast large pieces of armor. It was developed from the type of steel named "KO" and developed in France (Schneider) and UK (Vickers) in 1917. | 6 : Believed to be a subcontractor mark indicating who the part was built for (BU = Buick). Similar marks are CTC (Caterpillar Tractor Company), Ford (Ford Motor Company), and RRBCo (Reed Roller Bit Co.) | 7 : Believed to be the heat number [identifies what batch of steel is used] | 8 : Date of production of the part (month - year) |
