Welding Symbols & Blueprint Reading Flashcards

What does a 'melt-thru' symbol look like on a welding symbol?

Answer: A filled (solid black) circle below the reference line

The melt-through symbol is a solid (filled) circular dot placed on the opposite side of the reference line from the weld symbol, indicating full penetration from the arrow side.

In AWS welding symbols, what does 'PJP' indicate?

Answer: Partial Joint Penetration

PJP stands for Partial Joint Penetration, indicating the weld does not extend completely through the joint thickness.

On a sectional view of a blueprint, what do section lines (hatching) typically represent?

Answer: The cut surface of the material

Section lines (crosshatch lines) indicate the solid material that has been cut through by the imaginary cutting plane in a section view.

What is the purpose of a tail on a welding symbol's reference line?

Answer: To include supplementary information such as process, specification, or procedure

The tail at the end of the reference line opposite the arrow is used to provide additional data such as welding process (SMAW, GMAW), specification, or procedure number.

Which type of groove weld has only one member beveled at an angle while the other remains square?

Answer: Bevel groove

A bevel groove weld involves beveling only one member; the other member has a square (perpendicular) face, making it asymmetrical.

What does the term 'effective throat' mean in relation to a fillet weld?

Answer: The shortest distance from the root to the face of the weld

The effective throat is the perpendicular distance from the root to the theoretical weld face, used to calculate the weld's load-carrying capacity.

On a blueprint, what does a centerline (alternating long and short dashes) typically indicate?

Answer: Axis of symmetry or center of a circular feature

Centerlines mark the axis of symmetry for round features (holes, shafts, cylinders) or the geometric center of symmetrical parts.