General Information: The Type 90 helmet is named after the year of its design using the Japanese Imperial year system called “kōki.” Ninety is shorthand for kōki year 2590 which corresponds to 1930 in the Gregorian calendar. For this reason, the helmet is also referred to as the Model 1930 or Model 1930-32.
The Type 90 helmet was the helmet used by Japanese soldiers and sailors throughout the Second World War. The Imperial Japanese Army (IJA) version of the helmet was painted brown and had a five-point metal star on the front. The liner was made of three leather pads attached to a leather band. The chinstraps were a web type that were attached through metal rings riveted to the sides of the helmet. The Type 90s were marked according to size, either large or small, by a kanji character stamped into the rear metal rim. The same character was typically painted white in the back of the helmet presumably to make the size marking more readily visible. The helmets were also marked with an arsenal stamp also in the rear interior rim, to indicate the military arsenal where they were produced.
Displayed Example: This helmet was part of a WWII veteran’s collection of military relics. I had the impression that this was not something that the vet himself brough back, but I was never able to get the whole story. At any rate, I was happy to acquire this piece and knew it was going to be a keeper as soon as I pulled it out of the box. Faintly visible on the right side of the helmet is the name of person who brought this back from the Pacific. It is marked with the embossed and painted kanji characters meaning “large.” This is a stick figure with outstretched arms. It also has an “S” within a diamond shape embossed next to the size stamp. This was the symbol for the Kobe Seiko (steel) arsenal. The cloth material behind the liner pad has the Arabic number 17 for Showa year 17 which corresponds to the year 1942 in our Gregorian system. Both of the split pins are original WWII vintage, but one is a replacement.
Note that there were two calendar year systems used in Japan during the WWII period: nengō and kōki. In the nengō system the years are numbered according to the reigning years of the Japanese emperor. The WWII period corresponded to the Emperor Showa (Hirohito) whose reign was from 1926 to 1989. 1926 is counted as the Showa year 1, so 17 corresponds to 1942. The now mostly obsolete nengō system used the date of the founding of Japan by the Emperor Jimmu in Gregorian year 660 BC as the base year. The helmet model is named for the nengō year of its design but the liners were stamped with the kōgi year.
Collector Notes: Although the Type 90 was the only main helmet type used by the IJA during WWII, there some variations in configuration which are of interest to collectors. Many of these helmets were used with cloth covers and/or nets. In addition to the IJA Type 90s the Imperial Japanese Navy (IJN) also used the Type 90. Instead of five-point stars, these had metal IJN badges with anchors, or yellow stencils also with anchors. The IJN helmets were either brown, like their army counterparts, or they were grey. Because of the relatively high value of the IJN helmets, IJA helmets are sometimes found with post-war IJN badges and misrepresented as original IJN pieces.
* Citation pending