These are an American and British cast gray iron grenades, you can see a similarity in the metal surface with some of the fragmentation sleeves you have posted.
Can you see any evidence of a seam line on your examples?
The lack of a seam line does not mean that they were not castings though.
The Germans invented the Sodium Silicate-Ceramic Shell Lost Wax method of casting metal parts, the allies were in a big hurry to steal the process after the war.
Lots of detail in a casting and no parting line, cope or drag to worry about.
Less machining to do and all in all a much better casting.
And the casting medium can be ground up and used over and over again.
The fragmentation sleeve masters could have been cut in a hard "plastic" material and a mould made of it so long lengths of wax fragmentation "pipe' could be cast in iron by the ceramic shell process and cut to the desired lengths after.
Makes more sense than machining long lengths of pipe with all those grooves, plus the grooves look like they were cut in something soft first.
Run your finger nail back and forth through a piece of wax an see what I mean.
Below are the two grenades showing surface texture and the seam or parting lines where the two side of the sand mould came together.
Can you see any evidence of a seam line on your examples?
The lack of a seam line does not mean that they were not castings though.
The Germans invented the Sodium Silicate-Ceramic Shell Lost Wax method of casting metal parts, the allies were in a big hurry to steal the process after the war.
Lots of detail in a casting and no parting line, cope or drag to worry about.
Less machining to do and all in all a much better casting.
And the casting medium can be ground up and used over and over again.
The fragmentation sleeve masters could have been cut in a hard "plastic" material and a mould made of it so long lengths of wax fragmentation "pipe' could be cast in iron by the ceramic shell process and cut to the desired lengths after.
Makes more sense than machining long lengths of pipe with all those grooves, plus the grooves look like they were cut in something soft first.
Run your finger nail back and forth through a piece of wax an see what I mean.
Below are the two grenades showing surface texture and the seam or parting lines where the two side of the sand mould came together.
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