T-Joint

T-joints appear throughout structural fabrication wherever a vertical stiffener, attachment lug, or cross-member must be fused to the flat surface of a plate or beam web. The perpendicular orientation creates a natural pocket for fillet weld deposition on either side of the vertical member, and dual fillets provide superior stress distribution and fatigue performance compared to single-sided attachment.

When a T-joint is designed as a complete joint penetration groove weld, the vertical member is beveled and the assembly is welded from both sides to achieve full-thickness fusion, producing maximum joint strength at the cost of significant groove preparation and welding time. T-joints in machinery frames often employ fillet welds because the loads are distributed and the cost of groove preparation is not justified; by contrast, bridge and crane weldments typically specify CJP T-joints to maximize fatigue strength and meet strict welding standards applicable to public-safety structures.