In “Kugi”, it was noted that there was the nail with multiple actual dimensions for one nominal length of Japanese nail. According to Honto (estimation date) in 1803, the actual size of “hira-kugi” was about 90% of the nominal length. In addition, the actual length of “kashiramaki-kugi rui” was about 80% of the nominal length. Furthermore, the actual length of “kenchiku-you-kugi” was about 30 to 40% of the nominal length. In fact, it is not clear whether such a nominal length was used in “kenchiku-you-kugi”. And it is not clear in the past how nails that actual dimensions were about 90% or 80% were used together with “kenchiku-you-kugi”. The purpose of this article is to clarify how the actual size of Japanese nails, which is different from the nominal length, was distributed and established. The following points are clarified.
The example of adding letters such as “dai” in front of the nominal length of the nail is from ancient times in “Kenchiku-daijiten”, but the actual example is from the end of the 16th century. In the distribution of nails from ancient times, the “ren-kugi” that could be seen from the Heian period to the early Edo period were not seen after the middle Edo period. Until the early Edo period, the “ren-kugi” was used for nails of less than 3 sun, but since the middle of the Edo period, the description by the nominal length has come to be seen even for nails of less than 3 sun. In early modern times in Japan, there were nails with a nominal length of 90%, 80%, and 30 to 40% of the actual length for one nominal length. As you can see, the price of nails is widely distributed, and some price ranges were shown. The nails, which account for 30 to 40% of the actual length, have the same size system as “ren-kugi” used until the early Edo period, and it is considered that the nominal length was addressed to them. As a result, one nominal length has a plurality of actual size nails coexisting, and the actual price has shown a wide range. In addition, even after the middle of the Edo period, the numeral “wa” used in “ren-kugi” was used in part in the distribution of nails. Although “ren-kugi” was also used for nails of more than 3 sun, there were also cases in which one bundle was uniformly set to 100, not based on the idea of “ren-kugi”.
From the above consideration, it became clear that it’s difficult to immediately know the actual dimensions of the nominal length nails described in the literature since the middle of the Edo period. This is because there were at least three types of real-length nails for one nominal length in this era. Therefore, in order to know the actual length with respect to the nominal length, it is necessary to make a comprehensive judgment in consideration of where the nail is used and the price at the same time. By the way, after the Meiji Restoration, Western nails flowed into Japan. Since Western nails were distributed by using the numerical value in which the dimension based on the actual dimension was replaced with shaku-sun, the relationship between the nominal length and the actual dimension in Japanese nails was also corrected.
