Types of weld in steel structures

Types of weld in steel structures: Structural welding is a process by which the parts that are to be connected are heated and fused, with supplementry molten metal at the joint. A welding joint is a point or edge where two or more pieces of metal are joined together. They are formed by welding two or more workpieces (metal) according to a particular geometry. 

There are five types of joints  referred to by the American Welding Society (AWS) which are butt joint, lap joint, corner joint, edge joint and tee joint. In the field of steel structure fabrication and installation, arc welding is widely used.

Also see: How to understand welding symbols in steel detailing

Fig 1: Types of weld joints

Basic types of weld in steel structures

Welded joints can be classified on the type of weld, position of weld and type of joints.

• Fillet weld
• Groove weld or butt weld
• Slot and plug weld

Fillet weld

Fig 2: Fillet weld

The most common type of weld used for building structures is the "fillet" weld, which joins pieces at right angles. Fillet welds are typically more economical than groove welds due to less edge preparation.

The significance of the weld symbol’s position on the reference line is depicted in below figure 3.

Fig 3: Significance of weld symbols position

Groove weld

Groove weld is provided when members to be joined are lined up. It is costlier since it requires surface preparation. Groove welds are most commonly applied to butt joints and consist of the following types.

1. Partial joint penetrations (PJP)
2. Complete joint penetrations (CJP)
3. Flare-bevel groove welds

Groove welds can be partial joint penetration (PJP) or complete joint penetration (CJP) depending on the strength requirements.

Fig 4: Groove welds types CJP and PJP

Partial Joint Penetration weld

PJP or Partial Joint Penetration weld is a weld in which the weld metal does not reach the full thickness of the base material being welded but extends only through a portion of it.

Complete Joint Penetration weld

CJP or a Complete Joint Penetration weld is a weld in which the weld metal extends through the full thickness of the base material being welded.

Flare bevel groove weld

It is the type of weld which is used to connect a round surface and a planar surface.For instance, you want to connect a round pipe having some radius with a planar surface like a flat bar. For such cases, then you should use this type of weld to get a nice and clean finishing.

Fig 5: Flare bevel groove weld

Recommended for you: Exploring the Various Types of Weld Positions

Slot and plug weld

Slot and plug welds are used to suppliment fillet welds where the required length of fillet weld cannot be achieved.

Don’t miss: Stitch welding in steel structure

Conclusion

Steel structure welding plays an essential role in the manufacturing and installation process, the quality of steel structure welding directly affects the appearance, and also plays a vital role in the strength of steel structure building. As a detailer we should familiar with types of welds in steel structure.