Filletsvets

Filletsvets, known in English as fillet welds, are welds that join two surfaces at an angle, typically forming a triangular cross-section. They are the most common weld type used in structural and mechanical joints, including lap joints, T-joints, and corner joints.

Geometrically, the fillet weld size is defined by the leg length of the right triangle formed by the weld cross-section. The throat is the minimum thickness at the weld root, roughly 0.707 times the leg length in a symmetric 90-degree leg layout. Welds are designed to carry the expected loads for the materials and joint configuration; under-sizing can lead to failure, while over-sizing can add unnecessary reinforcement and heat input.

Fabrication and methods, The fillet weld can be produced by various arc and gas welding processes, including shielded metal arc welding (SMAW), gas metal arc welding (GMAW), flux-cored arc welding (FCAW), and gas tungsten arc welding (GTAW). Fillet welds can be deposited in flat, horizontal, vertical, or overhead positions. Edge preparation is minimal compared to groove welds, making fillet welds quick for joints with imperfect edges or limited access.

Quality and inspection: Fillet welds are commonly inspected visually and with non-destructive tests such as radiography, ultrasonic testing, magnetic particle testing, or dye penetrant testing, depending on criticality and standards. Common defects include incomplete fusion, cracks, porosity, undercut, and overlap. Accept criteria are defined by standards such as AWS D1.1 or ISO 5817.

Usage and considerations: Fillet welds offer versatility, speed, and ease of inspection but may have lower fatigue strength than full-penetration welds when joints face cyclic loading. They are widely used in fabrication, construction, and repair across various industries.