← Glossary

Joint Root Gap

The air gap is the distance between the workpiece edges that allows the introduction of filler material. It allows a finer joint and prevents porosity.

Physical-Chemical Mechanism of Action

The air gap is a defined space between the butt-joined workpiece edges. This space allows the filler material to enter the joint and create a tight connection.

Metallurgical Relevance & Welding Risks

An air gap that is too large can lead to porosity, which weakens the weld. An air gap that is too small, on the other hand, can make it difficult to feed the filler metal and result in incomplete fusion.

Workshop Practice & Instructions

For an optimal weld, an air gap of 0.1 to 0.3 mm is recommended. This value can be ensured by choosing the right welding process and proper workpiece positioning.

MetallurgieSchweißtechnik

AI Transparency (EU AI Act): Created on the basis of our own many years of practical experience in welding technology, with the help of AI, and reviewed editorially.

© 2026 Welder-World. All content is for training and continuing education and does not replace a certified welding procedure specification.