Sherman casting markings
By Pierre-Olivier Buan and Kurt Laughlin

For more information about Sherman casting markings, one can download / read this PDF file and visit this page from Hanno Spoelstra's website .

Several casting markings can be seen on various parts of a single M4 Sherman tank, and the meaning of these markings can seem very obscure to many people. However, they appear to have a kind of structure and to be very logical. Some parts of the casting markings don't have their meaning determined once for all, so any information that could confirm the exact meaning is very welcome.

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 (unknown) 7 : Believed to be the heat number [identifies what batch of steel is used] 8 : Date of production of the part (month - year)

marking 1    marking 2

marking 3    marking 4

marking 5    marking 6