Which of the following is NOT a basic joint type in welding?

The correct choice indicates that "Circular" is not a basic joint type in welding. In welding, the commonly recognized basic joint types are butt, tee, and lap joints.

A butt joint is formed when two pieces of material are aligned and joined at their edges. This is one of the most typical forms of joint used in structural applications due to its strength and straightforward fabrication.

A tee joint occurs where two pieces meet, forming a T shape. It is commonly used when a new piece is attached perpendicularly to another piece, making it essential in various structural welding scenarios.

A lap joint is created when two pieces of material are placed on top of each other and welded along the edges, providing a larger surface area for bonding and often used in joining sheets of metal.

The "Circular" joint type does not exist as a recognized basic joint configuration in welding techniques. While circular welding can happen in certain specialized applications (like in pipe welding), it is not classified as a basic joint type like the others mentioned. Thus, identifying "Circular" as the choice that stands apart from recognized welding joint types is accurate.