Temporary and Permanent Joints | Interview Question and Answers
Temporary and Permanent Joints | Interview ,viva , Oral Question and Answers
1. What are the purposes of screws?
To secure members
To transmit power
2. What is a stud?
A stud is a bolt in which the head is replaced by a threaded end. It passes through one of the parts to be connected and is crewed into the other part.
3. How is bolt designated?
A bolt is designated by a letter M followed by nominal diameter and pitch in mm.
4. How is a bolt designated? Give example.
A thread is designated with Letter M followed by Nominal diameter in mm and Pitch in mm [for fine pitches only]
If coarse pitches are used then P value is omitted. Thus M20×2.5 means, Nominal diameter is 20mm
2.5mm pitch, fine thread. M20 means, 20mm nominal diameter with coarse threads.
5. What is the meaning of bolt M24×2?
Bolt nominal diameter, d=24mm and bolt pitch, p=2mm
6. State the advantages of threaded joints?
- High clamping
- Small tightening force requirement
- Easy manufacturing
- Simple design
7. Define the term self-locking of power screws?
If the friction angle is greater than helix angle of the power screw, the torque required to lower the load will be positive, indicating that an effort is applied to lower the load. This type is screw is known as self locking screw. The efficiency of the
self locking screw is less than 50%.
8. Define welding?
Welding can be defined as a process of joining two similar or dissimilar metals with or without application of pressure along with or without addition of filler material.
9. Why are welded joints preferred over riveted joints?
Material is saved in welded joints and hence the machine element will be light if welded joints are used instead of riveted joints. Leak proof joints can be easily obtained by welded joints compared riveted joints.
10. How is welding classified?
1. Forge welding
2. Electric resistance welding
3. Fusion welding
11. What are the types of welded joints?
1. Butt joints
2. Lap joints
3. T joints
4. Corner joints
5. Edge joints
12. Define butt and lap joint?
1. Butt joint is made by welding the ends or edges of two plates.
2. Lap joint is made by two plates are overlapping each other for a certain distance. Then welded. Such welding is called fillet weld.
13. Define Tee joint and corner joint?
- T joint: the two plates are arranged in shape which means the plates are located at right angles to each other.Corner
- weld: Two plates are arranged at right angles such that it forms an angle.
14. When will the edge preparation need?
If the two plates to be welded have more than 6 mm thickness, the edge preparation should be carried out.
15. What is the minimum size for fillet weld? If the required weld size from strength consideration is too small how will you fulfill the condition of minimum weld size?
It is the defined as the minimum size of the weld for a given thickness of the thinner part joined or plate to avoid cold cracking by escaping the rapid cooling.
16. When will the weld deposit be weaker?
When the components are made of high carbon steel or alloy steel, the weld becomes weaker.
17. What is a rivet?
A rivet is a round bar provided with a head on one side and a tail on the Other side.
18. What is the different working processes used for making riveting?
1 Cold riveting 2 hot riveting
19. Name the possible modes of failure of riveting joint.
1. Crushing of rivets
2. Shear of rivets
3. Tearing of the plate at the edge
4. Tearing of the plate between rivets.
20. Define circumferential joint.
The ends of the plates are joined to the required length of the shell and to Close its ends.
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