Numbers, Numbers, Numbers....
It Can be Confusing!
Have you ever wondered how a World War II hammer C46008 became
hammer 5546008 in the late 1950s? This article will discuss drawing and
part numbers and excludes entirely the revisions as nothing here will
apply to revisions. In short, the information provided here pertains to
the basic number only, which is referred to by ordnance publications as
the part and/or drawing number. For ease I will use the term "part
number," as, usually, the part number and drawing number are the same,
unless reference is made to an entire assembly (but that's another
article for another time). To understand the system as it came to be
(i.e. hammer 5546008 or bolt 6528287), one must know about the World War
II system and its evolution.
The World War II system was around since the late 1920s and was
known as the Standard Nomenclature System or SNL. The SNL system, for
today's researcher, is simple and pretty clear. A referenced part under
the SNL system consists of a prefix and a basic number. The letter "C"
was the prefix and "46008" was the basic number of the part. Ideally
this basic number is unique and signifies only the hammer for the Ml
rifle.
The SNL system also provides a code to identify parts that were
packed for storage or issue. The format varied, but somewhere on the
package would be the code B021 or B21. B021- C46008 would allow somebody
to grab a printed SNL and find that B021 meant Ml rifle and C46008
meant hammer. Every major item within Ordnance Department
responsibility-including vehicles and tanks--had its own code.
As the war continued it became apparent that items developed during
the 1930's and earlier had four or five digit part numbers, but items
being developed by early war had six and seven digits numbers. By
mid-war groundwork was being laid for future uniformity by assigning
everything a seven digit part number.
In an effort to standardize all part numbers to a seven digit system, the following formula was adopted:
prefix |
*Drop Letter and Add to Basic Number** |
A |
5,000,000 |
B |
6,000,000 |
C |
5,500,000 |
D |
6,500,000 |
E |
6,900,000 |
This formula breaks down when a part number contains a letter
within its basic number. For example, D35410A became 7133230 in a random
assignment. (This is an assumption made by this writer as after many
attempts I am still unable to establish a pattern.) You can use the
above formula to convert wartime part numbers to later ones (pre-1954
and post-1954 will be covered in Part II). For those members who have
access to ORD 1, December 1950, you will find the formula on page 3.
The seven digit system is found in certain late-war SNLs, mostly
for later developed items, but the heavy push for adoption occurred
during the post-war period. As of January 1, 1954 the seven digit system
was mandatory for immediate adoption into the Federal Stock Number
system, which encompassed everything within the federal supply system,
not just ordnance items. The Federal Stock Number system (FSN) is
evident in the Technical Manuals of the 1960s and lasted until 1972 when
it was modified to the National Stock Number System (NSN). The FSN
system of the 1960s will be covered in Part Two. Having an understanding
of these systems will make researching technical manuals more
rewarding.
Notes: *prefix--These letters signify Drawing Size
with "A" being the smallest and "E" being the largest. Although not
applied during the war for small arms, the "E" size shows up in larger
items.
**Dropping prefixes was supposed to occur, but 1950s production had lots of Cs, Ds, and Fs.
For questions and/or assistance:
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