In　the　study,　ultrasonic　longitudinal　mode　guided　waves　were　employed　to　detect　defects　in　elbowed　tubes　(without　welds)　with　a　diameter　of　10　mm.　Finite　element　simulation　results　highlighted　that　the　emitted　L(0,1)　mode　guided　waves　experienced　strong　reflection　and　mode　conversion　at　the　elbow　region　to　generate　F(1,1)　mode,　followed　by　slow　and　weak　F(2,1)　mode.　The　guided　wave　reflected　from　the　elbow　with　a　through-wall　defect　was　manifested　as　two　overlapped　wave　packets,　which　were　good　indicators　of　a　defective　elbow.　To　conduct　L(0,1)　mode　guided　waves　inspection　on　the　small-diameter　elbowed　tubes,　a　novel　tailored　squirrel-cage　magnetostrictive　sensor　was　employed　in　the　experiment.　The　new　sensor　employed　the　configuration　of　segmental　iron-cobalt　strips　and　small-size　permanent　magnet　arrays.　The　entire　sensor　is　composed　of　two　identical　C-shaped　sensor　elements　and　can　be　recycled　and　installed　conveniently.　Experimental　results　obtained　from　healthy　and　defective　tubes　were　consistent　with　the　conclusions　obtained　from　finite　element　simulations.　An　artificial　through-wall　defect　at　the　elbow　and　a　notch　defect　at　the　straight　part　of　the　tube　could　be　simultaneously　detected　by　L(0,1)　mode　guided　waves　through　comparing　experimental　signals　with　simulation　results.