AWS AWS Joint Design & Preparation 2 — Questions and Answers
Question 1: What is the recommended minimum fillet weld size for a 3/4 in. base metal thickness per AWS D1.1?
- 1/8 in.
- 3/16 in. (Correct answer)
- 1/4 in.
- 5/16 in.
Correct answer: 3/16 in.
AWS D1.1 requires a minimum fillet weld size of 3/16 in. for base metal thickness between 1/2 in. and 3/4 in.
Question 2: Which weld joint configuration is most commonly used in structural steel construction for attaching a beam web to a column flange?
- Butt joint
- Edge joint
- T-joint (Correct answer)
- Corner joint
Correct answer: T-joint
A T-joint, welded with fillet welds, is the standard connection for attaching a beam web (or plate) to a column flange in structural steel work.
Question 3: 'Effective throat' of a fillet weld is defined as:
- The leg size of the fillet weld
- The distance from the root to the face of the weld, perpendicular to the face (Correct answer)
- The width of the weld face
- The depth of penetration into the base metal
Correct answer: The distance from the root to the face of the weld, perpendicular to the face
The effective throat is the shortest distance from the root to the weld face, and it is used to calculate fillet weld strength.
Question 4: What is the purpose of a 'backing bar' or 'backing strip' in groove welding?
- To preheat the joint before welding
- To support the weld pool at the root and ensure complete root fusion (Correct answer)
- To measure root gap alignment
- To shield the arc from drafts
Correct answer: To support the weld pool at the root and ensure complete root fusion
A backing bar supports the molten weld pool at the root pass, preventing burn-through and ensuring complete root fusion.
Question 5: What is the difference between a 'partial joint penetration (PJP)' and a 'complete joint penetration (CJP)' weld?
- PJP is only used in pipe welding; CJP is used in structural steel
- CJP achieves full depth fusion through the entire joint; PJP does not penetrate the full thickness (Correct answer)
- PJP is stronger than CJP
- There is no practical difference
Correct answer: CJP achieves full depth fusion through the entire joint; PJP does not penetrate the full thickness
CJP welds penetrate fully through the joint thickness, while PJP welds are intentionally designed to fuse only a portion of the joint.
Question 6: The 'weld access hole' (rat hole) in structural steel is used to:
- Allow the welder to access the back of a fillet weld
- Provide clearance for making a complete joint penetration weld at the flange-to-web junction (Correct answer)
- Reduce the weight of the beam
- Allow drainage of water from the joint
Correct answer: Provide clearance for making a complete joint penetration weld at the flange-to-web junction
Weld access holes are cut at beam flanges to allow unobstructed CJP welding of the flange and to reduce stress concentrations.
AWS AWS Joint Design & Preparation 2
What is the recommended minimum fillet weld size for a 3/4 in. base metal thickness per AWS D1.1?