In　order　to　study　the　effect　of　different　welding　processes　on　mechanical　properties　of　stainless　steel　fillet　weld　connections,　the　monotonic　tensile　tests　of　12　austenitic　and　12　duplex　stainless　steel　specimens　were　carried　out.　The　results　show　that　the　failure　surface　of　specimens　made　by　TIG　(Tungsten　Inert　Gas　Welding)　is　quite　different　from　that　of　specimens　made　by　SMAW　(Shielded　Metal　Arc　Welding),　and　the　latter　is　much　smoother.　Besides,　the　true　failure　angle　of　the　transverse　fillet　weld　connections　is　not　the　theoretical　value　of　45°　due　to　the　influence　of　the　complex　stress.　For　austenitic　stainless　steel,　the　strength　ratios　of　specimens　made　by　TIG　to　SMAW　are　1.03　(for　transverse　fillet　weld　connections)　and　1.13　(for　longitudinal　fillet　weld　connections),　and　the　ratios　of　relative　deformation　are　1.46　and　1.11.　For　duplex　stainless　steel,　the　strength　ratios　are　1.12　and　1.04,　meanwhile　the　relative　deformation　ratios　are　1.66　and　1.45.　The　connections　made　by　TIG　show　better　mechanical　properties.　For　the　two　stainless　steel,　the　strengths　of　transverse　fillet　weld　connections　are　much　better　than　those　of　the　longitudinal　fillet　weld　connections,　so　it　is　suggested　that　the　influence　of　the　increase　of　the　strength　of　transverse　fillet　weld　connections　be　taken　into　account　in　the　compilation　or　revision　of　the　related　specifications.　Copyright　©2021　Engineering　Mechanics.　All　rights　reserved.