What is Convexity in Welding?

Convexity is defined as the maximum distance from the face of a convex fillet weld perpendicular to a line joining the weld toes. This distance is measured at the centerline of the weld and is usually expressed in inches. Convexity plays an important role in welding because it affects the strength and integrity of the weld. Too much convexity can cause the weld to be weaker and more likely to fail, while too little convexity can make the weldless able to withstand stress.

The amount of convexity that is optimal for a given welding application depends on many factors, such as:

the type of metal being joined,
the thickness of the metals,
and the desired strength of the weld.

In general, however, a convexity of 1/16 inch or less is considered acceptable for most welding applications.

Excessive convexity in welding. What causes excessive convexity in welding?

There are several factors that can contribute to excessive convexity in welding, such as:

using too much welding current.
using too much electrode pressure.
using an electrode that is too small for the job.
moving the electrode too slowly.
not maintaining a consistent arc length.

All of these factors can cause the weld pool to become larger and more convex.

Should a weld be concave or convex?

The answer to this question depends on the specific welding application. In general, however, a weld should be convex if the goal is to achieve a strong and durable weld. Concave welds are sometimes used for cosmetic purposes, but they are not as strong or durable as convex welds.

How is weld convexity measured?

Weld convexity is measured by taking the maximum distance from the face of the weld perpendicular to a line joining the weld toes. This distance is usually expressed in inches.