Umemori, K. Hocker, A. Inoue, H. Kubo, T. Shimizu, H. Tajima, T. Watanabe, Y. Yamanaka, M. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-THAA04 English 1006-1011 THAA04 cavity electron SRF niobium vacuum Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-THAA04 http://srf2015.vrws.de/papers/thaa04.pdf In KEK-CFF, L-band SRF cavity fabrication studies have been actively proceeded. Main target of the R&D is investigation of cavity fabrication methods using different Nb materials. In this talk, we report mainly focus on the experiences obtained from single cell cavity fabrications. First, different Nb materials are compared, between fine grain Nb and large grain(LG) Nb from different vendors including low RRR LG Nb, in which, cavities were fabricated by electron beam welding method. Difficulty on LG cavity fabrication come from deformation due to stressed grain boundaries. In addition to nominal electron beam welded cavities, hydro-formed seamless cavities have been fabricated. Relatively large difference of equator and iris ratio cause difficulty on expansion of Nb pipes. Good qualified Nb pipe is essential and control of hydro-forming steps including annealing of materials is also important. In order to evaluate these cavity performances, vertical tests were carried out. Generally, they showed good performances. In this presentation, fabrication processes, technical difficulties, mitigation strategies and vertical test results are presented.