What is a Root Bend Test in Welding?

The root bend test is a welding test in which the weld root is on the convex surface of a specified bend radius. This test is used to evaluate the mechanical and metallurgical properties of a weld joint. The root bend test is often used in qualification tests for welding procedures and welder performance.

The root bend test can be used to assess the following properties of a weld joint:

Mechanical Properties: Tensile strength, yield strength, elongation, fracture toughness.
Metallurgical Properties: Macro- and microstructure, hardness, impact toughness.

How do you perform a root bend test?

This test is usually performed on a welding specimen that is machined from the actual weld joint. The root bend test can also be performed on a weld bead deposited on a plate or pipe.

The root bend test is sometimes confused with the flare groove weld test, which is a similar test in which the weld root is on the concave surface of the bend radius.

What are the types of bending tests?

There are three main types of bending tests:

Flexural test.
Compressive test.
Torsional test.

Each type of bending test is used to evaluate a different property of the material being tested.

The flexural test is used to measure the material’s ability to resist deformation under tension. The compressive test is used to measure the material’s ability to resist deformation under compression. The torsional test is used to measure the material’s ability to resist deformation under torsion.

What are the units of measurement for bending tests?

The units of measurement for bending tests are typically expressed in pounds per square inch (psi) or megapascals (MPa).

What is a side bend test in welding?

A side bend test in welding is a test in which the weld is deposited on the concave surface of the bend radius. This test is used to evaluate the mechanical and metallurgical properties of a weld joint.

What is root bend?

Root bend is the condition of a weld bead being deposited on the convex surface of the bend radius. This is often done in qualification tests for welding procedures and welder performance.