Recommended Effective Throat Sizes for Flare Groove Welds to HSS

An experimental research project has been undertaken to investigate the geometric properties, and in particular the effective throat size, of flare bevel and flare-V partial joint penetration groove welds at the corners of Hollow Structural Sections (HSS). HSS-to-plate (flare bevel) and HSS-to-HSS (flare-V) single-pass welds were carefully performed to Welding Procedure Specifications agreed within a Project Oversight Committee, using ASTM A500 tubing, then cross-sectioned after inspection to produce 180 test welds. Parameters included three HSS sizes (with wall thicknesses ranging from 3/16 in. to 3/8 in.), four welding processes (FCAW-G, FCAW-S, GMAW and SMAW) and four welding positions (flat, horizontal, vertical and overhead). All weld cross-sections were polished and etched, then had their profiles digitally recorded and measured. An analysis of the resulting data has shown that the current pre-qualified effective throat sizes for these two weld types, in AWS D1.1/D1.1M:2004, can be made more liberal for most weld processes.