Degtyarev, A.Itenberg, I.Sertöz, A.S.2018-04-122018-04-1220170025-5831http://hdl.handle.net/11693/36377We show that the maximal number of (real) lines in a (real) nonsingular spatial quartic surface is 64 (respectively, 56). We also give a complete projective classification of all quartics containing more than 52 lines: all such quartics are projectively rigid. Any value not exceeding 52 can appear as the number of lines of an appropriate quartic. © 2016, Springer-Verlag Berlin Heidelberg.English14N25Primary 14J28Secondary 14J27Article10.1007/s00208-016-1484-01432-1807