BS1139 right angle coupler 1.BS1139 products. 2.Clearly mark letters. 3.Perfect surface. 4.Timely delivery. BS1139 right angle coupler used for the connection of two tubes at right angles RIGHT ANGLE COUPLERSDimensions:48.3 x 48.3mm (1 29 / 32" x 1 29 / 32" )Material:drop forged carbon steelBolt: T-boltNut sizes:17mm, 19mm, 21mm, 22mm, 23mmStyles: standard, flangedStandards:BS1139 (1982 & 1991), ...