@article{oai:rekihaku.repo.nii.ac.jp:00001147,
 author = {齋藤, 努 and 高塚, 秀治 and Saito, Tsutomu and Takatsuka, Hideharu},
 journal = {国立歴史民俗博物館研究報告, Bulletin of the National Museum of Japanese History},
 month = {Mar},
 note = {application/pdf, We analyzed the pieces taken from five iron swords of various kinds, which were excavated in Hokkaido. From the metallurgical structures of the surface and cross-section, the chemical compositions of inclusion and micro-vickers hardness we found the followings;
1. Inclusion in all the samples lengthened in the longitudinal direction, which meant that material iron was forged out in this direction.
2. All the sword was made with steel and the concentration of carbon varied in each sample.
3. Three of the samples, No.2391, 3909 and the “sample without identification number”, contained inclusion with iron-titanium oxide. They were considered to have been smelted with iron sand as raw material.
4. From the metallurgical structure of the “sample without identification number”, a warabite sword, we found the concentration of carbon decreased gradually from inside to surface. It was estimated to have been manufactured with a decarbonizing process of steel with higher carbon content.},
 pages = {177--188},
 title = {北海道出土鉄製刀剣類の自然科学的分析結果（第２部　研究論文）},
 volume = {107},
 year = {2003},
 yomi = {サイトウ, ツトム and タカツカ, ヒデハル}
}