Screw Thread Test - 2

1. What are the values of constants for whit worth threads?

a=0.002, b=0.003, c=0.005

a=0.003 b=0.005, c=0.002

a=0.001, b=0.002, c=0.003

a=0.004, b=0.005, c=0.006

2. Which of the following is incorrect for the minor diameter tolerance of effective diameter for internal threads?

For 26 tpi : Tolerance = 0.2p+0.005”

For 26 tpi : Tolerance = 0.2p+0.004”

For 26 tpi : Tolerance = 0.2p+0.007”

For 22 tpi : Tolerance = 0.2p+0.005”

3. What is the formula for tolerance on effective diameter (D = major diameter, L = length of engagement, p = pitch, a, b, c are constants)?

a∛D +b√L +c√p

a∛D +b√2L +c√p

a∜D +b√L +2c√p

2a∛D +2b√L +3c√p

4. How many variables are taken into consideration for the calculation of effective diameter tolerance?

5. What is the relation between close fit and free fit?

Close fit tolerance is three fourths of free fit

Close fit tolerance is two thirds of free fit

Close fit tolerance is one half of free fit

Close fit tolerance is one third of free fit

6. How the values of constants affect the accuracy of tools?

Increase in accuracy will increase the value of constants

Decrease in accuracy will reduce the value of constants

Decrease in accuracy will increase the value of constants

Increase in accuracy will reduce the value of constants

7. What is the minor diameter tolerance of effective diameter for external threads?

Effective diameter tolerance+0.02√p & Effective diameter tolerance+0.01√p

Effective diameter tolerance+0.013√p & Effective diameter tolerance+0.02√p

Effective diameter tolerance+0.03√p & Effective diameter tolerance+0.01√p

Effective diameter tolerance+0.01√p & Effective diameter tolerance+0.02√p

8. Why Wide tolerance on core diameter of internal threads is given?

To prevent binding at the face of the tap

To prevent binding at the flank of the tap

To prevent binding at the root of the tap

To prevent binding at the crest of the tap

9. Match the following fit with their use?(A- Fit, B-Usage)

	     A						B
	1) Close		a) Suitable for bulk of screw threads
	2) Medium	        b) Suitable for screw requiring fine snug fit
	3) Free			c) Suitable for interchangeable screw threads

1-b, 2-a, 3-c

1-c, 2-b, 3-a

1-a, 2-b, 3-c

1-b, 2-c, 3-a

10. What is the major diameter tolerance of effective diameter for external threads?

+0.01√p

-0.05√p

+0.05√p

-0.01√p