Spigot tube couplers for fluid flow sets and devices are provided. The spigot tube coupler includes a stop surface and a spigot extending from the stop surface and configured to be inserted into a tube. The spigot includes an insertion end, a fluid port, an outer surface and a plurality of grooves disposed around the outer surface. The plurality of grooves are configured to receive a bonding agent to provide a plurality of bonding areas between the spigot and the tube. Methods for assembling a spigot tube coupler and a tube are also provided.