Welding blueprints contain abbreviations, reference lines and arrows. The abbreviations state the processes that the welder must carry out on each joint, while the reference line shows where the welding should be done. If there are multiple tasks, the reference line breaks into separate arrows. A break in the reference line means that a joint preparation is necessary. Different styles of breaks indicate different preparations. Symbols around the arrows indicate which side the weld should be done.
Each style of weld has its own symbol. If the symbol is below the reference line, the weld should be performed on the side that the arrow is pointing to. A symbol above the reference line indicates a weld on the joint's other side. Symbols exist for bead, fillet and plug welds, as well as a variety of groove welds.
Welding blueprints also include numbers that show the angles and lengths for each weld. The numbers' placement in relation to the reference line indicates which side of the joint is in question. Other symbols include a flagpole, which indicates that the weld should be done in the field as opposed to in the shop. A circle around the end of the reference line indicates a weld all around, such as when fitting two pipes together. Forked tails at the end of the reference line indicate special instructions such as which type of weld to use.