Threaded Joints in Machine Design topics include: Screws, screw jack, threaded joints, uniform bolt strength, and loads based on the principle of eccentricity. Threaded joints are mechanical joints that use threaded fastenings to hold machine parts together. They are also known as separable joints because they can be disassembled without damaging the parts.  Here are some types of threaded joints: Direct threads: Use direct screws to attach the component pieces. Indirect threads: Use standardized components like bolts, screws, and nuts to hold the component pieces. Acme thread: A... Show more

Threaded Joints in Machine Design topics include: Screws, screw jack, threaded joints, uniform bolt strength, and loads based on the principle of eccentricity.

Threaded joints are mechanical joints that use threaded fastenings to hold machine parts together. They are also known as separable joints because they can be disassembled without damaging the parts. 

Here are some types of threaded joints:
Direct threads: Use direct screws to attach the component pieces.
Indirect threads: Use standardized components like bolts, screws, and nuts to hold the component pieces.
Acme thread: A modification of square thread used in screw cutting, lathes, and bench vices.
Knuckle thread: A modification of square thread with rounded top and bottom, used in necks of glass bottles and large molded insulators.
Buttress thread: Powers transmission in one direction and has the advantage of square and V thread. 

Threaded inserts, also known as threaded screw inserts, are essential to machine design components. They are usually invisible because they sit within joint holes. Threaded inserts provide structural robustness to a joint. 
The thread series refers to the standard number of threads per inch, and there are four classes: coarse (C), fine (F), extra fine (EF), and constant pitch. 

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Machine Design Practice Test: Threaded Joints in Machine Design

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25 Questions

1. A differential screw is defined as a mechanical device consisting of two screws connected in parallel.

MaybeTrueDon't KnowFalse

2. Determine the secondary shear stress acting on the bolt 3 and its direction. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel.

4500N vertically down6100N vertically up

3. Set screws are subjected to tensile forces only.

Both compressive and tensileYesCan’t be determinedNo, they are subjected to compressive forces only

4. What is the output from differential screws when pitch of the two screws is 12mm and 8mm? Also the nut is rotated by applying a force of 120N at a radius of 300mm and the two screws remain stationary. The torque of raising and lowering for the two screws is 5k N-mm and 2.5k N-mm where k is the effective axial weight on the screw.

17200 N-mm19200 N-mm15200 N-mm13200 N-mm

5. A flange of radius 200mm is fastened to the machine screw by means of four cap screws of pitch circle radius 150mm. The external force P is 20kN which is loaded at 160mm from the machine screw. There are two dowel pins to take shear load. Determine the maximum effective tensile force acting on the bolt. The four bolts are equally spaced radially.

7777.7N6777.6N4777.6N5777.6N

6. If for a trapezoidal thread, angle of thread is 15’ then what will be the replacement of the coefficient of friction which is 0.15.

0.15530.16670.17760.1335

7. A fillet weld is an approximately triangular cross section joining two surfaces lying parallels to each other.

FalseDon't KnowMaybeTrue

8. What type of friction in cup design is recommended for the set screw?

SlidingNone of theseStaticRolling

9. The structure shown is subjected to an eccentric force P=5kN and eccentricity=500mm. The horizontal distance between two bolts is 200mm and vertical distance between bolts is 150mm. The yield strength of bolts is 400N/mm² and factor of safety is 3. Determine the resultant shear force on the bolt lying right and above the CG.

6047.44N5989.32N5047.44N654334N

10. The shock absorbing capacity of bolt can be increased by making the shank diameter ________ the root diameter.

Greater thanNo effectLesser thanEqual to

11. The structure shown is subjected to an eccentric force P=5kN and eccentricity=500mm. The horizontal distance between two bolts is 200mm and vertical distance between bolts is 150mm. The yield strength of bolts is 400N/mm² and factor of safety is 3. Determine the size of the bolts.

8.68mm10.74mm9.23mm11.54mm

12. The transverse shear stress at the root of the threads in the nut can be given by?(symbols have their usual meaning, z=number of threads in nut)

4W/πdz²4W/πtd²W/πdtzNone of these

13. Which type of threads is recommended for fluctuating loads?

Either of fine or coarseNone of the listedCoarse ThreadsFine threads

14. If bending stress in a screw is of magnitude 95N/mm² and torsional shear stress of magnitude 15N/mm², then what is the principal shear stress?

48.7N/mm²54.3 N/mm²49.8 N/mm²51.4 N/mm²

15. Shank is the portion of bolt between the head and the thread.

Don't KnowTrueMaybeFalse

16. Find the torsional shear stress to which a screw of nominal diameter 22mm is subjected when the clamp exerts a force of 5kN on it. The screw is double threaded and pitch of screw is 5mm.Given: Coefficient of friction is 0.15.

21.29N/mm²25.45N/mm²35.65N/mm²31.21N/mm²

17. The shock absorbing capacity of bolts can be increased by

Increasing the shank diameterNone of the listedIncrease the shank diameter and decreasing the length of shankDecreasing the length of shank portion of bolt

18. Resilience is defined as the property of material to absorb energy when deformed _________ and to release this energy when unloaded.

PlasticallyNone of the listedElasticallyUp to fracture point

19. A machine vice whose length of the handle is 150mm and the coefficient of friction for thread and collar are 0.15 and 0.17 respectively has a force applied at handle of 125N. Also the outer and inner diameters of collar are 55mm and 45mm respectively. Find the clamping force W if nominal diameter=22mm and pitch=5mm.

3657.56N2868.73N2134.34N4539.45N

20. What will be efficiency of the screw in case of raising the load when coefficient of friction is 0.1553 and tangent of helix angle is 0.0813?

43%34%45%54%

21. Given data for bracket is P=20kN, e=100mm, S(yt)=400N/mm², FS=3. If distance between the bolts from the axis of tilting is 125mm and 25mm, then find the effective tensile force acting on the bolts lying at 125mm from tilting axis.

8798.2N6765.2N7692.3N7962.11N

22. Determine the primary shear stress to which the bolts are subjected if P=3kN.

2000N3000NNone of the listed1000N

23. A wall bracket is attached to the wall by means of 2 identical bolts, one at A and one at B. The force of 20kN acts at a distance of 400mm. Bolt A lies at a distance of 50mm from axis of tilt and bolt B 500mm. Allowable shear stress in the bolts is 100N/mm² and tensile is 40N/mm². Determine the size of bolts using maximum shear stress theory.

18mm12mm9mm16mm

24. If there is no place to accommodate the nut, then one would choose the

StudsThrough BoltsNone of theseTap Bolts

25. In the following figure, two plates are fastened by means of two bolts. The yield strength of bolt is 400N/mm² and factor of safety is 4. Determine the permissible shear stress in the bolts.

100N/mm²25N/mm²50N/mm²75N/mm²