Lot stamp suffix number

[Twthmoses]

Never really known what the suffix number after a lot number meant, well still do not, but this little gem I found in a Watertown Arsenal report might give an idea.

This is from a report dealing with seam welding process, edge annealing and delay cracking. Memorandum Report No. WAL 710/612 from 13. April 1944. I quote;

…” The four submitted helmets were fabricated from Sharon Steel Corp. heat no. 73191 and are included in Schlueter Lot 213B. Two of the helmets were fabricated from discs contained in spider No. 2 and two from spider No. 3. The numbers stamped on the inside of the visors are as follows
Edge-annealed helmets 213B2, 213B3. Regular production helmets 213B2, 213B3.”…

I do not know what a “spider” is in a metal production facility, but suspect it is a station, stand, row or machine. Is it possible that this suffix number is to identify a specified machine/station in a production line?

Ever noticed how this suffix number always seems to be later stamped. Always a little offset, in both spacing and high. Like it is applied after the lot number, which according to the above it very much seems like. Maybe this suffix number is simply to be understood as this lot or part of it, has been part of some test, were it was needed to know exactly which equipment made the shell.

Anybody have other information on this suffix number?

[Rescue190]

It is my understanding the suffix used corresponded to the lift number of the same heat lot from the steel maker. The example provided that I had read in a published article was Lot #596 was the first batch from a particular lot of steel sheets. 596A was the next batch from the same lot number and so on. The next heat lot was assigned a new number.

Credits: The information came from a journal of the research was published in Military Collector & Historian. I saved the PDF article thought I should not attach.

John

[Twthmoses]

Yes that is also my understanding, but i takling about the additional number after the letter, that some shells have, like 136F 3.
I know this very good article you referenced to. He even has examples of these types of numbers, but does not talk about them in the text.