More information please! Are you referring to  AWS B2.1:2009 - Base Metal Grouping for Welding Procedure and Performance Qualification? If so, this book doesn't have Table 4.1 as you mentioned earlier. Could you please re-check and confirm!

Dear Jorge Giraldo,

It is unfortunately where I have read a different edition (2005 edition) from yours which made me a little bit confusion. Back to your enquiry I would like to extract a paragraph from AWS Welding Handbook Volume for your understanding about bend tests as below:
Question 1

"Bend tests provide a means to evaluate both the ductility and the soundness of welded joints. These tests are performed by bending a strip of the weldment to a specified radius. The outer surface of the bend specimens is subjected to extensive plastic yielding in tenson, which can cause fractures or fissuring in less ductile material or open existing weld defects such as porosity and lack of fusion. Thus, when weld defects or hard, brittle zones are present, bend tea specimens consistently fail.

Test specimens can be bent in a tension test machine (free bend) or wrapped around a mandrel of a specified diameter (guided bend). Most codes require guided bends but provide for the use of alternative test equipment, such as the bottom-ejecting guided bend test fixture, roller-equipped guided bend fixture, and the wrap a round guided bend test fixture..."

So, once code mentions "Bend Test" it means you can perform "free bend" or "guided bend", if the code requires "guided bend" it means you are not allowed to do "free bend".

Question 2

Recessed Ring is a kind of backing ring used for welding. It is applied for one side welding in certain cases where we are not able to access the weld from both side.

Hope it is clear enough for your enquiry or if you may have further requirement, let us keep on discussing...