Welding symbols: arrow side and other side

Drawings show weld requirements as symbols: where the weld goes, the joint type, and the weld’s size and amount.

Those symbols help you share weld requirements with designers, fabricators, and other inspectors. AWS A2.4 provides this common way to communicate.

Every welding symbol starts with a reference line and an arrow that points at the joint.

The arrow touches one side of the joint. That side is the arrow side.

A fillet triangle below the line means weld the arrow side. The number on its left is the leg size.

The fillet symbol sits above the reference line. Where does the weld go?

1. Arrow side
2. Other side
3. Both sides

Answer: Other side. Above the line is the other side. Below is the arrow side. Both means both.

Above the line, the weld moves to the other side of the joint.

Next lesson: Fillet and groove weld symbols